Known Bugs

This page is for a list of bugs that have been discovered. They are separated into Confirmed and Patched.

Determined Pac-man Glitch
When a Pac-man Bloon is popped and the player clicks main menu before it disappears, Pac-man will still be there, and it can still go anywhere around the main menu before the time runs out. (link to video)
 * This happens on all Bloons Games excluding Bloons Junior.

Exploding Ice Bug

 * Bloonsworld glitch.gif happens occasionally in some Bloons World levels. When more than half screen is filled with Bomb Bloons, only some of them will pop, then they suddenly freeze and explode. There is no exit from this glitch other than closing the player's browser. This can be tested on the Bloonsworld level 759 or 3796143. (link to video)

Frozen Pac-man Bloon Glitch

 * If a Pac-man bloon gets frozen, it doesn't appear to be frozen, but it can't be popped unless the Lightsaber Bloon, the Bomb Bloon or Pac-man from another Pac-man Bloon touches it.

Spike Rubber Bypass Glitch

 * Very often, when Spikey Bloons fall down and there's a Rubber Block under them in a position that is not the lowest row of the screen, the spikes will bypass the Rubber Blocks and will fall off the screen. This can be tested on the Bloonsworld level 1265859(more effective) or 3795343(less effective).

Dart Rubber Bypass Glitch

 * When the dart gets in a position which is surrounded by 5 or more metal blocks, the dart will touch the Rubber Blocks like if it does only one bounce then it'll go in the opposite direction: if in the same direction there immediately is another Rubber Block, the dart will bypass it. This can be tested on the 46th level in Bloons Player Pack 3 (whose Bloonsworld code is 1100657): however, it requires a very careful aim, as to complete the level the dart must go rightwards popping the other bloon.

Dart Rubber Bypass Glitch 2

 * Throwing a dart at a Rubber Block being close to the monkey will make the dart bypass it. This can be tested on the 50th level of Bloons Player Pack 1 throwing the dart rightwards at high power.

Quicker Bonus Dart Bloon Popping Glitch

 * Sometimes the Bonus Dart Bloon can get popped when the dart is close to it, but not over it. This can be tested on the 37th level in Bloons Player Pack 3.

Quicker Bomb Bloon Popping Glitch

 * Throwing a dart at a Rubber Block/Metal Block being close to the monkey, at high power will let the dart bypass the block and pop the Bomb Bloon, if there's one. This can be tested on the 12th level of Bloons Player Pack 2 (whose Bloonsworld code is 594832 and 3795344) by throwing the dart leftwards.

Not Popped glitch

 * When the screen is completely filled with Tack Bloons or Pac-man Bloons, some of those may not get popped. This can be tested on Bloonsworld code 3795326 (tacks) or 3795338 (pacman).

Revolving Boomerang glitch

 * Occasionally, when a boomerang comes close to the monkey after flying a circuit, it stops and rotates on the spot. Sometimes, the player will have to restart the level to make it vanish. Other times, it will eventually disappear. To make the glitch happen, the player has to throw it directly to the right. It can be tested on Bloonsworld code 3796656.

Vanishing Monkey Glitch

 * When the hot air bloon pops at the very top and the monkey falls, the monkey vanishes before reaching the trees (probably intentional).
 * This is probably caused by the fact the blimp will get destroyed by trees. However because there is no blimp, it acts like a black hole and if the monkey reaches there, he will get "sucked in" and disappear.

Invisible Pursuer Glitch

 * When the monkey falls, a board comes up saying the player's score and the player's highscore. However, the player can still hear bloons popping until the player makes the game reset (by trying again or going back to the main menu).

Hint Glitch

 * After earning 200 points, the player has unlimited hints, even if the player has no points . Even though Bloons Pop 3 is a few years old, Ninja Kiwi hasn't yet patched the glitch, and most likely never will.

Iced Bug 1

 * Sometimes when the Ice Tower attacks, some bloons will stop but not appear to be frozen.

Hypersonic Speed Tack Shooter Bug
The player will appear to have their money decreasing as it pops bloons. In reality, the player has negative money, although the negative sign is not showing, and is actually gaining money. When the money reaches zero, you can now see your money increasing.
 * There is no need to be upset.png the player presses tab until the Faster Shooting box is surrounded in a yellow box while it can be afforded, press the space bar until the attack speed is hyper-sonic and the upgrade is bought. Then, most bloons can't get by that tower. This glitch can be done by other towers (such as Dart Monkey with infinite piercing darts, Ice Tower with unlimited freeze time, Most Towers With Infinite range(Still shoots just as far!), however those do not actually work.

Buy for Afford glitch

 * Sometimes, after the player accomplishes the Hypersonic Speed Tack Shooter bug, part of the "Buy for" button appears in the "Can't afford" screen for the upgrades. This usually happens with the Tack Shooter the player does the glitch on, but it can happen with any tower, as shown by the slideshow below:

BTD2
(Note that every BTD1 glitch works in BTD2 as well.)

Laser Vision Bug

 * In BTD2, the Laser Vision upgrade pops frozen bloons, but it makes the sound a sharp projectile when it hits a frozen bloon.

Double BOOM! Bug

 * When placing a Bomb Tower, it will shoot a bomb, then after the bomb explodes, another explosion sound is heard, even though the second bomb is not fired or detonated.

Huge missile bug

 * Giant missle.jpgimes, when the Missile Launcher shoots it will shoot an abnormally large missile. As seen on Superjombombo2's throwback series E5 (Seen on picture on the right)
 * This only happens when the Bigger Bombs upgrade is purchased, this may have been done on purpose due to the name of the upgrade.

Lack of Money Bug (Very minor)

 * Beacon_glitch.png BTD3, the player can place a Monkey Beacon when the player can't afford it. The player can choose where to place it. However, it says not enough money. and it won't be placed. It doesn't happen with all the other towers.

Monkey Beacon bug

 * This works only in BTD3. The player must have a Monkey Beacon with the Monkey Storm Beacon upgrade, it will allow the player to activate Super Monkey Storm. Then, sell the Monkey Storm Beacon, the Super Monkey Storm will still be there and the player can use it unlimited times without having the Monkey Storm Beacon, despite the description of the upgrade says that it allows it to call Super Monkey Storms.

Place Towers Anywhere

 * This glitch allows you to place towers anywhere on the map. First, click on the tower you want to place. Then, right click anywhere on the track where you ARE allowed to place that tower. While the drop-down is still there, click where on the screen you want to place the tower.

Super Pineapple Explosion bug

 * In BTD3, sometimes the Pineapple will pop 2, or even 3 layers of bloons.

Melee Bug 1

 * The boomerangs/glaives that the boomerang/glaive thrower is holding count as projectiles, meaning any bloon that runs into them will be popped. Strangely, the held boomerangs/glaives do not appear to have a pop limit. Also, the player can't see it, so it could be the one on its head.

Start Round Glitch

 * On the first track in BTD3, sometimes there will not be a start round button after a round. The player has to use super monkey storm to get the button back. This is more common on easy difficulty.

Orientation bug

 * In HD versions of Bloons TD, when the player adjusts the volume, the orientation appears to be sideways even though the orientation is completely normal.

BTD4 Challenge Restrictions bug

 * In the Sweet Tooth challenge (pass in Easy mode using only Dartling Gunners and Spike Factories), the player can use a Dart Monkey by pressing its hotkey (D). The dart monkey still functions normally.

Beacon Bug

 * In BTD4, some towers covered by the Monkey Beacon's range will not get affected by its additional effects.

Corrosive glue is not corrosive bug

 * Sometimes in BTD4, the glue gunner's corrosive glue will not pop bloons on fast forward.

Spike Storm glitch

 * The Spike Factory's final upgrade, Spike Storm will sometimes only cover up half or only a fourth of the screen in BTD4.

Road Spikes Not On Track

 * On BTD4, if the player hovers Road Spikes half on the blue space with the player's rank, XP, round, and the Pre-Round Comment, the player's NK account, or the final side of the track, the player can place the Road Spikes there, even though they can only be placed on the track.

Rank 99 bug

 * In BTD4, when the player level up, it says that the player has rank 99, but on the other rank thing at the bottom, it says rank 2. Players can get very excited over this, but it's actually a bug.
 * This can happen for any other rank as well.

Black Patch Glitch

 * Around Round 80 (or lower on laggy computers), A black patch will appear where a lot of action is going on. There is no known fix to this. Also sometimes, the spikes fired by a spike factory have a black square around them. (This may be just an imagination, but this seemed to happen more often when a bloon buster mortar fired at a spot within the spike factory's range.) This happens due to the fact that the computer can't handle all the graphics. Happens earlier on tracks with complicated backgrounds.
 * Placing lots of road items on one spot will result in this bug also.

Medal Glitch

 * If you complete, lets say Ocean Road easy, and you complete a challenge, that Ocean Road easy medal will disappear, but a new medal will show up under what you just did (MOAB madness: Kiwi medium, Lollipop challenge: Lollipops easy, etc.)

Upgrade Glitch

 * Upgrade anything to level 3 or higher, then as it's upgrading, buy another tower. That tower will show the same upgrade for the other tower. You just skipped a couple of upgrades! However, lets say you skipped all the upgrades but the sun god, your super monkey will have a small range (sadly).

Place Towers Anywhere

 * This glitch allows you to place towers anywhere on the map. First, press the hotkey of the desired tower you want to place. Then, press the hotkey of one of the road items where you ARE allowed to place it. Quickly click, and press the hotkey of the desired tower you want to place. This can take a few attempts before successfully doing the glitch.
 * This does NOT work with dartling guns or spike factories, as there is no hotkey for either tower.

Spike Factory Cramming Bug

 * When spamming multiple spike factories together in a narrow spot near the edge of the screen (e.g. rightmost space in the Fireworks track), some of them will deploy spikes off the track and make some players lose.

Iced Bug 3

 * On laggy computers, bloons can completely freeze and stop near the front. They will become impoppable and no more bloons will spawn. Exiting the track will not erase them, and so does switching tracks. The player will have to restart the game to get rid of them.

Round 0 Bug

 * Sometimes before you start a game a comment will appear saying "Round 0 passed. 99 money awarded", but you won't get the extra cash.

Disappearing Boomerang Bug

 * Boomerang Throwers' boomerang/glaive/lightsaber will always disappear before it can even come back to the tower, even if it hasn't reached its pierce cap. This has never been fixed due to Ninja Kiwi no longer updating this game.

Save Bug

 * Saving the game requires a MochiGames account. Ever since MochiGames shut down, the player's game hasn't been able to save, save, even if the player presses the Save button in a game.

Leveling Delay Bug

 * Whenever a tower is upgraded, its "level" (shown above the selected tower's name) stays the same until the player either clicks it again or deselects it and selects again.

Dartling Gun Bug

 * Bug 1: Sometimes in fast forward, the Dartling Gun shoots 2 streams of darts. It is more common when it is upgraded to Increased Barrel Spin.
 * Bug 2: (Does not work with Laser Cannon) When Fast Forward is active, sometimes the Dartling Gun's shots reach bloons; the darts will not pop the bloons.

Double Missile Bug

 * In BTD4 or BTD4E, if the game is in fast forward, briefly a second missile can be seen launched from the Missile Launcher.

Iced Bug 2

 * This bug is very rare. When a bloon is frozen by an Ice Tower, the bloon will stop forever, and it cannot be thawed or affected by the towers or road items, and the player needs to exit the game. This is more common in BTD4 and BTD4E.

Skip Round Lag Bug

 * Sometimes, when the player starts a round in BTD4 or BTD4 expansion, the game will freeze, and then the round will be completed. The player will get their reward money, but no bloons will appear on the screen. This is a lot more rare in BTD5, but it is most seen on slower computers in BTD4. It happens most often in the first few rounds, but it may also happen in late game levels or the MOAB Madness mission on BTD4.

Melee Bug 2

 * The boomerangs that the Boomerang Thrower shoot, will not return to the tower; instead, they will vanish at about 2/3 of the way (with Fast Forward on). And even if Fast Forward is off, the boomerangs will not pop any bloons after that, but they will still be present. This does not happen in BTD4 iOS.

Explosion bug

 * In BTD4 and BTD4 Expansion, if there are a large amount of bloons that the Bomb Tower is attacking, the game will not show the explosion, only the frags (from the Frag Bombs premium upgrade). This can also happen with the Mortar Tower; it only shows the bloons' layer popping. This is caused by lag.

Monkey Glue Bug

 * In BTD4, the player can place Monkey Glue off the track. It is often around the borders.

Road Spikes Jump bug

 * In BTD4 and BTD4 Expansion, there is a glitch where fast bloons can travel a short distance over road spikes before popping, causing the bloons that spawn from them to miss the road spikes completely. This also happens with the road spikes produced from Spike Factories.

Loud SFX Glitch

 * When you unlock the Super Monkey at Rank 15, you will hear the unlock sound effect, but way louder than usual.

Pineapple Bug

 * In this game, if you use a pineapple, you can see a second explosion behind the pineapple explosion.

Banana Farm On Deflation Bug 1

 * Deflation cheating.png is possible to get a Banana Farm on Deflation by pressing its hotkey (F). However, it gives no money.

Black Area Bug

 * In Bloons TD 4 Expansion, and on the Subterranean Sewers track, around round 45, there is a bug similar to that on BTD4; a black patch may appear in the middle of the track. It gets bigger and smaller at the edges, but it gradually gets bigger, covering a 3-4 inch square of the track by Round 50.

Track 6 Bug

 * If the player plays track one on BTD4 expansion and save, and then when the player goes to the original BTD4, it will take the player to Firecracker. Also, if the player quits BTD4 and reload the save, the player should click on Resume Game. The player might see a message saying Congratulations! You passed this track on null. The player can also earn an achievement for this.
 * If the player clicks "Keep playing in freeplay mode", then the player just starts from whatever round the player was at when the player quits BTD4. The player can even save.
 * Beating the track on the difficulty it was on still gives the player the You beat this track on (difficulty) notice, and then it becomes freeplay.
 * Sometimes, the player can't click Resume game. When this happens, go to any track, and the player has passed it on null.

Specialties bug

 * In BTD4 Expansion, if the player uses the Vehicles specialty, it reduces the cost of Monkey Buccaneers and Monkey Aces, but it increases the cost of their upgrades.

Error by creating new towers bug

 * In BTD4 Expansion, and in the towers menu, when the player hovers the cursor on the Dartling Gun or Spike Factory, it shows the image of the Dart Monkey instead of the image of the Dartling Gun/Spike Factory.

Locked Bloons Bug

 * In BTD4 Expansion, the player sometimes cannot play in the Subterranean Sewers track. If the player clicks Start Round, the round will only send up to 5 bloons (the other bloons will be locked at the beginning of the track), and if they reach the exit, the player loses lives, but the player can't start the next round. Then, if the player quits the game and play on another track, the locked bloons will remain on the track, and the player's towers cannot pop them.

Covered Menu bug

 * The tower description is covered by the bottom of the screen. See the photo for more.

Monkey Ace Bug 1

 * In the Monkey Temple track, if the player puts an un-upgraded Monkey Ace before starting round 66, in the current round and round 69, Monkey Ace will shoot 6 darts instead of 8. This is more likely to occur if the player is playing on Hard difficulty.

Farm Glitch

 * When selecting a farm, sell it, then quickly select another tower before the upgrade menu disappears. The farm will disappear, but it will still give its income when the round ends (there is no visual display of the +80 though). With Monkey Tycoon, you can get infinite cash this way.
 * For apopalypse mode, you can simply exit in and out of the game to gain infinite cash (and lives, with Healthy Bananas) that way too.

Non-Arctic Arctic Wind bug

 * In BTD4 iOS, Ceramic Bloons popped from a M.O.A.B. do not get slowed down by arctic wind if they are popped in its Range. The Bloons can still get frozen, however.

Playing after the player loses bug

 * In BTD4 iOS, there is a glitch where if the player loses, and the player exits, and re-enter the saved game, the pause screen will appear; and if the player taps the resume button, the game will play for one frame. Towers will shoot, Bloons will pop, and the player can even get rounds to end, and even start the next round if the player taps the button during the one frame that the game is playing. Unfortunately, entering and exiting the game multiple times to keep playing is a very long and boring process.

Unplayable bug

 * In the mobile versions of Bloons TD 4, "monkeying around" with the menu buttons might cause the player to be stuck on one screen, forcing the player to restart the application.

Debug Glitch

 * Sometimes when "monkeying around" with the menus, you can enter a game with infinite cash (doesn't work with challenges or deflation).

Unachieveable

 * A severe bug causes achievements to disappear, even if the player has gotten them.

Tower Staying Bug

 * When you select a tower, then exit the track, and then open it again, you'll see the tower info at the bottom.

Blinking Hotkey Bug (very minor)

 * When you select a tower and then press the hotkey for the same tower without placing it, the range circle will blink red for 1/10 of a second. Probably intentional since the circle blinks red when you select a tower, so you basically re-place it.

Lag Bug

 * Bug 1: In BTD5, if the player clicks the Sell button very fast, the player can click the button 2 times and the player gets twice the money. Happens frequently in laggy computers. (patched now)
 * Bug 2: On laggy computers, if the player has only one tower with an ability, and if the player clicks the button many times during a lag spike, the ability can be used more than 1 time (for example, the player has only one Spike Storm ability, but the player can use it 5 times). This ability can also be used when there are more than 1 of the ability. This is best result with Supply Drop Sniper Monkeys, where player may receive much more money. Best used with auto-clicker on co-op match, where both computers and internet connection between slows down game significantly.

Ability Locking Bug

 * In BTD5, if the player loads a game that has towers with abilities, the abilities become unusable until they recharge again (this is probably intentional to prevent the player from getting a "cheating" kind of advantage). Precaution: Only save at round 1~46, 49, 59, 69 & 79 to avoid unusable ability.

Double Fire Glitch

 * If a tower is upgraded when it is doing the pre-firing animation, it will have its attack interrupted, and will instead fire two upgraded shots afterwards.

Can Not Place Towers Bug

 * Sometimes, when you place road spikes or pineapples in large amounts with a clicking macro, you cannot place any more towers.

Hypersonic Fail Glitch

 * On mobile, Hypersonic Spike-O-Pult Glitch doesn't work, and instead you get a Super Monkey that shoots a Spiked Ball at the normal rate. Also, 3/x or 4/x Dart Monkeys can be transformed to a Super Monkey that shoots a Spiked Ball.

Infinite Range Fan Club Bug

 * Use super monkey fan club many times (If you're lagging while doing so you have a higher chance) and it should eventually show the range equivalent to a Sniper Monkey (the small range circle) http://puu.sh/56V5u.jpg

Hotkey bug

 * When using the Dart Training Facility (Level 3) building, and if the player uses the hotkey Q for placing a free Dart Monkey when available, but the player doesn't have enough money for placing a normal Dart Monkey, the hotkey Q does not work, and the player has to use the button in the tower menu to place the free Dart Monkey. The same goes with Spikes R Us level 3 building with the Road Spikes.

Harmless Towers

 * If the player gets 6 MIB Call to Arms and a 2/4 Boomerang Thrower, and the boomerang thrower is within the range of the MIB Call to Arms, activate all 6 MIB Call to Arms, and then a second later, activate Turbo Charge. For a few seconds, the Boomerang Thrower will shake around. Then when the MIB Call to Arms ability ends, the Turbo Charge will act like a normal Turbo Charge (On fast forward, this doesn't happen).

I Don't like Red Hot 'Rangs bug

 * Red_Hot_Rangs_Glitch.png the player has a Glaive Thrower and upgrade it to Red Hot 'Rangs, the glaive in the monkey's hand looks like a normal glaive until the monkey throws it, then it comes back to the tower, and it becomes a Red Hot 'Rang.

Ninja Always Seeking Bug

 * Sometimes, an x-0 ninja monkeys shurikens will seek anyways, even though you haven't upgraded him to do that. Cannot send his shurikens far distances if this is active, but can make course corrections to the weapon.

Ninja 1/1 glitch

 * Conversely, sometimes a 1/1 Ninja doesn't seek.

Shadow Double glitch

 * A ninja's shadow double's range will stay if it disappears while clicked on.

Bomb on frozen black bloons bug

 * When a bomb tower's bomb hits a frozen black it makes the sound of a sharp object hitting a frozen bloon along with the explosion. Also the explosion has no effect on nearby bloons.

Melee MOAB Assassin bug

 * Bug 1: Sometimes a MOAB assassin will instantly kill a MOAB-class bloon with its normal shooting attack when you haven't used the ability. For example, a MOAB assassin is attacking bloons when a MOAB comes. You don't click the ability, but when the tower launches the missile like normal, the missile will kill the MOAB in 1 hit. Like the ability, it does 753 damage to ZOMGs with this bug.
 * Bug 2: This is rarer than bug 1. If you have a MOAB assassin and click the ability, the tower will only do its normal damage to the MOAB. Like if there's a MOAB, and you click the MOAB assassin again, the tower won't kill the MOAB but just do x10 damage to it like a MOAB mauler.

Popping-less Bug

 * Glue Gunner's pops are inaccurately measured when multiple bloons pop at the same time (from splitter bloons or splash upgrade). For example, a White Bloon is glued. White layer counts as one pop, and the resulting bloons pop simultaneously, so the two bloon pops count as one.

Meerkats don't like Corrosive Glue Bug

 * Normally, a 2/2 Glue Gunner looks like a 2/0 Gunner. However, when placed within the range of a Meerkat Spy, they'll look like a 0/2 Glue Gunner.

Outstripped Glitch

 * An ill-placed x/3 Buccaneer will miss most bloons (including reds) completely and therefore cause leakage. Although this happens with other towers (even Super Monkeys), x/3 Buccaneers placed a little bit away from a large bend in the track suffers the most.

Monkey Pirates Glitch

 * If you buy a monkey buccaneer and upgrade it to monkey pirate,the MOAB Takedown ability will still be in effect if you sell the tower while taking down a MOAB or a BFB. This will cause the MOAB class bloon to look as if it's being dragged to the bottom of a lake.

Blind Dart Storm

 * Sometimes, when upgrading Spy Plane to Operation: Dart Storm, the tower will start to look directly at the right instead of rotating. It's only an appearance glitch and does not affect the gameplay. The glitch fixes itself when upgrading to Ground Zero. This is because of the Sniper Monkey ability Supply Drop Ability.

Temple on Weird Angle bug

 * Play one of the tracks until you get a temple. Save, then quit the game. The next time you play, the temple will sometimes be on a weird angle.

Temple Outline bug

 * Similar to Temple on weird angle, but this time if you place the temple and look at its white outline, it will be on a different angle to the temple. (the default one)

Temple of the Monkey God Bug

 * TOTMG Blink glitch.gif the Temple of the Monkey God stops firing, its eyes will be blinking as if it is still firing. This bug was removed but it came back when three new tracks (Fireworks, Tunnels, and Country Road) were added.

Outside the Range bug

 * Sometimes, the Super Monkey will attack out of its range, even when there are no M.O.A.B. Class Bloons.

Harmless Towers

 * If the player gets 6 MIB Call to Arms and a 2/4 Boomerang Thrower, and the boomerang thrower is within the range of the MIB Call to Arms, activate all 6 MIB Call to Arms, and then a second later, activate Turbo Charge. For a few seconds, the Boomerang Thrower will shake around. Then when the MIB Call to Arms ability ends, the Turbo Charge will act like a normal Turbo Charge (On fast forward, this doesn't happen).

Monkey Village Harming Bug

 * Placing a Monkey Village near a Bloonberry Bush will unintentionally reset the amount of spikes it has.

Mortar Tower SFX Bug

 * After buying Bigger Blast, the mortar explosions will not be heard. This does not apply to the Mobile version and Bloons Monkey City.

Invisible Death Beam Glitch

 * In some games (usually on Sandbox Mode), if a MOAB appears right after all bloons on screen have been popped, the Ray of Doom will become invisible.

Bloon Area Is Blind Glitch

 * Sometimes, if you have a dartling gun upgraded to Bloon Area Denial System and no bloons incoming, the gun will fire straight up, no matter where you aim it. Weirdly, this does not work with Hydra Rocket Pods. Rockets can still pop bloons when this way. Aims normally when bloons come. On Sandbox mode in BTD5, the gun will fire this way when you haven't sent bloons and none are onscreen.

Burning the Track

 * In sandbox mode if you put all final upgrade paths on the track, hold down P for 10 seconds, and wait for all ZOMGs to get popped, sell all the towers - somehow, the fire from the X/4 monkey apprentice will remain on screen and does not vanish.

Allergic Meerkats Bug

 * Normally, a 2/2 Glue Gunner looks like a 2/0 Gunner. However, when placed within the range of a Meerkat Spy, they'll look like a 0/2 Glue Gunner.

Monkey Village Harming Bug

 * Placing a Monkey Village near a Bloonberry Bush will unintentionally reset the amount of spikes it has.

Hypersonic Tower Exploit

 * If you use Call to Arms a 0/x tack shooter, then upgrade it to 2/x, the tacks/blades will shoot at a hyper-sonic speed, much like the one in BTD1/2. This also works with bomb, mortar, buccaneer, dartling gun, sniper, and ninja. This was in Bloons Monkey City too, but as of v150831, it is no longer possible.

Anger Issues Glitch

 * Rarely happens, even when bloons haven't leaked, angry squirrel will be end up berserking permanently. This happens during rounds on random occasions.

Bad Aim Bug

 * Sometimes towers will attack to the left away from the bloons and still pop them in BTD5. This happens frequently with fast firing towers, such as Plasma Blasts.

Fast-Forward Bug
On old or slow computers, the screen freezes when you turn off fast-forward gameplay goes back to mormal when you activate fast-forward again.

Undo Tower Placement bug

 * Sometimes in Co-op Mode, the game does not allow the player to place towers, sending the message Tower placement declined. Your ally placed a tower there before you, and the player needs several tries before placing them. This usually occurs when the player is on low quality and the player's ally is not, making the game detecting the tower on an illegal position (for example, in the opposite side), or when the player places more towers very close to each other.

The Teleport Bloons Have Been Added in co-op bug

 * On a laggy computer, if you play on co-op and you get a big lag spike, all bloons on screen (including MOAB class bloons) will skip very far in the map, and mostly to the exit. This bug tries to fix itself by freezing the game completely or blacking out the game (but not the border including Towers, Agents, etc.), but it doesn't work. Sometimes they don't count as leaks, but most of the time they do, resulting to a loss of lives or game, depending on what bloons leak. This bug makes it very difficult to win a co-op track on hard.

Full House Infinite Towers Glitch

 * By having the shadow ninja double ability unlocked, you can use the ability, click on the shadow ninja, and sell it. This will allow you to buy 1 extra tower. You can perform this multiple times to increase the amount of towers you can place.

Short-Lived Bug

 * Sometimes, the game messes up on how many rounds are left for the player's tower in the mission. Most commonly, it skips a round, so the player's tower(s) only has 9 rounds instead of 10.

North Pole track bug

 * Sometimes, the North Pole track doesn't appear correctly in the "Tracks" menu. You can fix this glitch by closing and opening again the menu.

Reverser Difficulty Bug

 * Advanced Reverser, Expert Reverser or Extreme Reverser can be achieved on any difficulty.

No Monkey Sub in Special Missions

 * Very minor, but before it was announced on the site with the Monkey Sub update, the player could not use the Monkey Sub in Special Missions. This was fixed when Ninja Kiwi intentionally announced the Monkey Sub.

Endless sound of the falling monkeys (Flash)
 * During the loading screen, when you press play at the moment the monkey falls, you'll her that monkeys falling forever. To stop it, reload the page

Game Over after new game bug if it's laggy

 * Sometimes, when the player loses a game, and after the player starts a new game, the game will show the pop-up that says the player lost the previous game (and the round where the player lost).

RBE bug

 * In Apopalypse Mode, in an update, the RBE of the round does not change; it stays at 24 (or some other random number if on fast track) independently from the round the player is playing.

Invisible 4/4 Tower bug

 * If the player places a tower, hits backspace or delete, and clicks on the spot where the tower was without moving their cursor at all, an upgrades bar for the sold tower will appear at the bottom. It will have no Official Artwork. The player upgrade it to 4/4 (if it remains 3/1 or 1/3 and the player buys the less upgraded path first).
 * This bug used to give you invisible abilities, however that is no longer possible, due to the Monkey Sub update. It still deducts money though, making it practically useless.

Go Button Glitch

 * Main menu glitch.png laggy computers, sometimes the Go button will appear when a round is not done. Also, the Go button can appear in Sandbox mode.
 * If you click the button when that happens, you'll see the next wave of bloons come as well as this round's bloons.
 * If it appears in Sandbox mode, and you try to send bloons, the bloons won't come until you hit the Go button.

Automatic Chest bug

 * Sometimes the Treasure Chest gets opened without clicking, and the Monkey Money will not get deducted, and the days in a row streak will still count.

Glitchy Chest Bug

 * Sometimes, the player can't click on the Monkey Money chest. Refreshing the game helps. Sometimes though it will tell you to wait until the next day to try again, thus also losing your day in a row streak.

Main Menu Bug

 * When the player wants to leave a game, and sometimes when the player leaves the border of their previous game, Towers, Special Agents, Lives, Money, etc. Will be around the Main Menu (see picture).

Main Menu Glitch 2

 * This is sort of the opposite of the main menu glitch; if the player clicks the menu button, the game will still show, but not the border.

Delicious Banana Glitch

 * In BTD5, if the player clicks play while the title screen monkey is eating his banana, the eating sound will continuously play with no end, even when the player goes onto a track. The player can fix this by refreshing the page or closing the browser then going back on the game (this also happens with the other title screen sound effect after the logo comes up; that sound is the monkey falling). This can also happen with the fireworks sound.Screen Shot 2013-07-23 at 2.16.47 PM.png

Playing In Main Menu bug

 * When the player is severely lagging and clicks the home button many times in quick succession, and clicks yes, then play another track, there will be another box saying Are you sure you want to quit?.

Achievement Glitch

 * Sometimes, when the player taps on a achievement and wait, it will become invisible, but some letters of it will remain.

White Screen Of Death

 * Sometimes, with a bad connection, and when the player loads BTD5, it loads like normal, but the player logs in as a guest (or on rarer occasions, as a user). After a few seconds this happens: (see photo)
 * It sounds like the "monkey eating banana on top of the BTD5 letters" screen. If the player clicks GO!, nothing happens. Clicking on the dart monkey will cause the monkey to appear on the top left corner.
 * It says round 12345678 and RBE 1234567 at the bottom of the screen.

Grey Unlock Glitch
If you unlock a tower in a mission where you can't use it, the picture will still be greyed-out as if it were locked. (discovered on Bloons Tower Defense 5 HD, not tested online)

Crash your Chest
If you open the game and click the chest, sometimes your Flash player will crash at the precise moment that the monkey money is about to be added to your stash. If you reload, it will say you already opened the chest but you won't get the monkey money. This is not a very common glitch.

Infinitely Falling Monkey
When you first pull the game up and the play button pops out of the ground, if you click it at a specific moment as the monkey is falling onto the 'Bloons TD 5' text, the sound effect of the monkey falling will play over and over again. This sound continues even if you start playing a track. It can be only fixed by reloading the page.

Non-overclocked tower Glitch

 * To achieve this glitch, get any tower and a Monkey Engineer upgraded to Overclock. Then use overclock on the tower. You'll notice it shoots hyper-sonic. Then, while overclock is still effective on the tower, upgrade it. You'll notice it will not shoot hyper-sonic, but just shoot at normal speed without Overclock. This also works with M.I.B call to arms. However the hyper-sonic speed is another glitch and will only be achieved sometimes.

Maximum Enhancements Bug

 * Sometimes, on the special mission The Crucible, if you try to use Overclock on a tower in a socket of power, Overclock will have no effect on the tower's speed at all. Also works with M.I.B call to arms.

Bloonchipper Bug

 * Sometimes, the Bloonchipper pops all layers of bloons in one shred.

Rank 53 Profile Wipe Bug

 * Sometimes, at Rank 53, it will wipe your profile of the game off the computer.

Meerkat Seizure Glitch

 * Occasionally, the meerkat spy's head will rapidly jerk from side to side, giving the illusion of a seizure.

Bloon Area Is Blind Glitch

 * Sometimes, if you have a dartling gun upgraded to Bloon Area Denial System and no bloons incoming, the gun will fire straight up, no matter where you aim it. Weirdly, this does not work with Hydra Rocket Pods. Rockets can still pop bloons when this way. Aims normally when bloons come. On Sandbox mode in BTD5D, the gun will fire this way when you haven't sent bloons and none are onscreen.

Piercing Bombs Bug

 * On version 2.0 and below, when you had a Monkey Fort in the range of anything that wielded explosives, the explosives would pierce the bloons (So it looks like it pops 2 layers). This was fixed on version 2.1, but only fixed for Bomb Towers.

Monkey Money bug

 * In BTD5 iPhone/iPod Touch/HD, the player can get infinite monkey money by changing the day of their mobile device ahead by 1 and opening the treasure chest. This also happens in PC versions (but only for deluxe). Though, repeating this may not be recommended as it may not be functional after a few "days".
 * After this bug has been exploited, the chest stops working until it is actually the day after the "day" the chest was last opened.

Noob Engineer Bug

 * If you upgrade a monkey engineer to 0-4, then upgrade it to 1-4, the engineer's appearance and thumbnail look like a 0-0 engineer. It still has its normal functions, and this can be fixed once you upgrade it to 2-4. This was fixed in 2.1, but when the Odyssey mode was introduced, the bug was put back in, but now only the appearance is changed.

Temple Bug

 * If there is a sun god placed on top of a pontoon, upgrading to a temple will sacrifice all the towers around it (including the pontoon as well), do its animation and then unintentionally disappear.

Achievement Bug

 * Rarely, some achievements will reset themselves back to 0% (like impoppable, steely, etc.), besides the streak achievements which are the daily challenge ones. If it happens on a track achievement, winning that track will refund you the achievement.

Co-Op Ace Private Hangar Bug

 * On Android, If the Ace Private Hanger is activated while playing in Co-Op mode, Aces do not have the auto-aim dart attack.

Firing Bug

 * Sometimes with most towers, they look one way but fire somewhere else. It can happen in any track.

Super Monkey Spike-O-Pult

 * (Only works in BTD5 iOS) If the player activates the Super Monkey Fan Club ability, it will affect Juggernauts and Spike-O-Pults as well, but they will only shoot darts. Oddly, they also shoot Spiked Balls/Juggernaut Balls at ordinary fire rate.

Performance Drop

 * When there are fireworks (after the player completes a track), going into Freeplay Mode will cause significant performance drops.

Wacko sentry bug

 * Sometimes, when a 1-0 monkey engineer is placed near the track/edge where you cannot place towers, a sentry is spawned on the track/edge.

Spike Factory Glitch

 * Sometimes, the Spike Factory won't place spikes on the track. However, if the bloons touch them, they will still pop.
 * Other times,it will produce spikes between rounds(happens when round ends as the spike factory is producing Spikes when the Round ends.)

Banana Farm Glitch

 * If a 3/x banana farm is upgraded to 4/x AFTER the round starts, you will get 13 boxes of bananas. In later rounds, you can sell the banana farm, redo this glitch, and gradually gain money.

Losing Rewire Bug

 * If bloons come in and are about to leak, you can hit pause and quit. Then you can re-enter the game from the previous round. This is very useful in missions like Wizard Lord as the player can get forewarnings against MOAB rushes.

Volume Bug

 * In version 1.2 of Bloons Tower Defense 5 Mobile, the music gets noticeably quieter after the player resets the track.
 * This can be fixed by opening the pause menu and closing it.
 * This also happens in Bloons Monkey City Mobile.

Special Missions Bug

 * If you complete a Special Mission, and close BTD5 without exiting the victory screen, the game will save. After that, the game will continue as normal, except you will be playing with your current towers.
 * If you do this, you won't get a victory screen for passing the victory rounds (50, 65, 85)

Cheaper Village Bug

 * If you place 2 Monkey Villages by each other and then sell one of them, the unsold Monkey Village's upgrades will still be the same price as it was when there was another Village by it (10% off every upgrade). Quitting the game and then resuming it will cause the prices to go back to normal. This bug is present on every mobile version of BTD5 (BTD5 Mobile, Battles, and Monkey City)

Saved Money Bug

 * If you complete MOAB Madness and exit, go to the main menu screen and click the save button, the game goes to the screen with your towers you had at the end of Moab Madness with also 30,000 starting cash at Round 2.

Headprint glitch

 * The 0/2 boomerang tower's artwork lack the marking from its head.
 * This appears in BTD5, older versions of BMC, and the mobile versions (except for BMCM)

Temple Bug

 * When an opponent has a temple of the monkey god, the game will only show the temple using its original sun rays, without any sacrifices. This causes lots of lag.

Time Slow Bug

 * When playing a game, time will appear to move extremely slowly. This is because of a bad processor or low internet connection stability.

Energy Bug

 * Most of the time when the player gets energy in Bloons TD Battles, there is "Negative Time", where time goes negatively and the player never gets energy until the player reloads the page.
 * After refreshing, on rare occasions, the energy regen time then rises to a huge amount (over 100000 hours), preventing you from gaining more energy. The only way out is to purchase an energy potion from the shop and get the energy to max to clear the timer or to contact Ninja Kiwi. You may be able to get away with refreshing the page again or logging out and then logging back in, but usually it rarely works.

Harmless Towers

 * Some Towers will not shoot with its weapons sometimes. This happens commonly with Glue Hose, Turbo Charge and very often with Boomerang Thrower/Glaive Thrower/Ricochet/Lord and Mortar Tower with Rapid Reload in BTD Battles. It is unknown why this happens.

Purchasing Bug

 * Very rare, when a player purchases something from the shop the game will crash, the medallions will be taken and the tower or upgrade will not be given. The only fix is to contact Ninja Kiwi.
 * Sometimes, when purchasing energy potions or max energy boosts, they will not give the energy (still gives the max energy though) and unlike the towers and upgrades, the game doesn't crash.

Monkey Ace flying away bug

 * Sometimes when a Monkey ace is brought it will fly off the screen and in to the opponents screen, and It will not be able to pop any bloons until it gets back on your screen.

Disconnection bug

 * Rarely, on Defense mode on BTDB HD, if the internet disconnects, it won't throw you out of the game. Instead, no bloons appear, but you can still gain/take benefit of Income. The game will throw you out when you place down spikes.

Hypersonic Spike-O-Pult Glitch

 * To accomplish this glitch, the player needs a 2,0 Dart Monkey and a 0,4 Dart Monkey. Then, the player should activate the Super Monkey Fan Club Ability and upgrade the 2,0 Dart Monkey into a Spike-o-Pult, but it is only hyper-sonic for 10 seconds. This also works on Juggernaut as well, allowing the player to easily obliterate ceramics and MOAB-class Bloons.

Closing Error

 * When the app opens, it shows the loading screen, quickly followed by the ninja kiwi screen and then closes completely (or crashes), unable to play and when double pressed the home button on iPad, the apps thumbnail is of the menu screen and when pressed it too force closes. Apparently the reason for this is when the home button is pressed while still in a match without pressing surrender or on a screen that says "Victory" or "Defeat", then entering after a couple minutes.

Corrupted Matching System bug

 * Since April 17, 2014, the player may only battle opponents that have a similar battle score to the player's (must not have a 10000+ difference). This sometimes occurs and sometimes not. NK confirmed that this wasn't done intentionally, but it's unknown why this happens. Does not happen on private matches.

Boomerang Thrower Glitch

 * If you have a 2/2 Boomerang Thrower, the glaives will appear normal until thrown, and when they come back they turn normal again.

16 Second Finding Match Bug

 * When you try to find an opponent, while waiting for the game it will disconnect you from the server when the loading game times reaches 16 or in rare cases 15 or 17 seconds. However, when you enter the screen again time will go on like normal with out stopping at 16 seconds. This bug can be quite annoying.

Cheap Win

 * If you skip the map when the tower selection screen reaches the last second, your opponent gets a random tower loadout. Your opponent will be unable to change the towers since the Ready button will be pressed automatically. However, your opponent can still counter the trick by skipping the map after you do before you choose your towers and press Ready. Technically this is not a glitch but a strategy, though.

Busted Audio

 * On the Everyplay update, SD versions of the game has audio that is messed up. The music will sometimes make a screeching sound and bloon pops will sometimes sound like snow. The sound sounding like snow was fixed on the next update but the music could still screech. This was completely fixed in a later update.

Battle Energy Bug (Mobile)

 * Go into Private Match/Practice, and use all your Battle Energy rolling the extra tower. Then, go to your device's Settings and change the time forward. Your Energy will go to 20, and if you quit the Private Match/Practice menu, you get your Battle Energy back. You can keep doing this and get hundreds of Battle Energy.
 * In short, run out of energy, and then change your time forward.
 * If you revert back the time after you got back your energy, nothing will be changed.

Kill Screen

 * Very rare, on mobile you can get a loading screen that says "Connecting". It is actually a kill screen, and it will make your game crash if this happens.

Invisible Sun God Bug

 * A glitch occasionally occurs with the Sun God: its head will become completely invisible/transparent.

Bloon Cycle Bug

 * When viewing the .SWF file or using another method of seeing outside the screen, if the game is paused while Bloons are spawning they will loop through bloon types from red to ceramic repeatedly. When the game is resumed the bloons spawn as the normal type.

Red Blop Counter Bug

 * The player can get 100% Red Blops even though there are still Red Blops in a level. Only known to exist in level 3-5, due to the amount of bloons there.
 * Sometimes it occurs in level 1-5 just for collecting all Red Blops from all non-lead bloons

Join The Club Earlier Bug

 * The player can get the achievement "100% Club" if the sum of every level played's Red Blops collected % is equal to 500%.
 * If you do the math, however, 500% divided by 5 levels is precisely 100% red blops collected in a level, so of course you would get the achievement.

Upgrades lost glitch

 * When the player closes BSM2, then log back in again, the player may lose all the upgrades the player has purchased. Refreshing the game will make the upgrades re-appear.

Mirrored Boss glitch

 * Sometimes in the last level (3-5) in Deep Bloon Sea in Bloons Super Monkey 2, the boss will glitch and it will display a mirrored boss in the upper corner while the real boss might come down all the way to the end, quicker than normal, making the player lose the level.
 * Sometimes, Heavy Metal Bloon bugs out and also gets cloned. pic

Ninja Kiwi flashing lock bug

 * Occasionally, BSM2 will give the player the message "play now on Ninja Kiwi" when the player plays the game on Ninja Kiwi. This only happens when the player is attempting to log in.

Wrong Background Glitch

 * When you play a level in hardware, it shows the true background of the level you are playing. However if you change to software, the level shows the incorrect background.

Third Boss Glitch 2 (AKA No Boss Glitch)

 * When bronze is obtained near the end of 3-5, the boss will not appear and the player completes the stage.

Upgrades Not Bought Before bug

 * This seems to be the opposite of the Upgrades Lost glitch. When starting the game at Stage 1-1, a player by the name, Ninjakiwimine2 experienced a glitch that he has Fire Wave upgrade for Left Arm (Magic Upgrade 3), even though he hadn't bought it. This glitch is also possible when Intense Magic and Fireball upgrades aren't bought.

Black blob of Fire Glitch

 * On Software mode, Elemental Strike will look like a big black blob with a flame in the middle. When this happens, switching to Hardware mode will cause the game to turn into the background color of the zone.

Super Monkey still has the Golden Bloon/Power-Up Bloon's Power-up when the player quits a Level Glitch
Example: Pop the Golden Bloon or the Power-up Bloon on the Fourth Stage of Monkey Lane and collect the Power-up (i.e.: The Wizard Lord Power-up). Quit the Level and view the Upgrades Menu. Super Monkey still looks like the Wizard Lord, even though the player quits the Level.
 * When the player quits a Level while the Super Monkey still has a power from a popped Golden Bloon or a Power-up Bloon, and when the player goes to the Upgrade Menu, Super Monkey still has that power.

Not so real Glitch

 * When player beats a level without touching or doing anything, earned blops will be different than before.

Beacon on building Glitch
Sometimes,the bloon beacon will appear on a building. To fix, move the building. it is possible to capture a captured area for more easy loot.

Wrong City Level Glitch

 * If you go into the My Cities selection screen, it will say that your city in Grassy Pass is in a city level higher than the actual city level in the first city. (e.g. your first city is level 24 but the My Cities selection shows that the first city is level 25.)

Cash Starve Glitch

 * Sometimes when you go into your city, all your Banana Farms will not produce any city cash. To fix this, reload Bloons Monkey City again.

Pacifist Mode Glitch

 * Sometimes when Pacifist Mode is on, your city can still get attacked even though Pacifist Mode is activated.

Game pausing

 * Also works in BTD5.
 * When you buy a 4/0 ninja monkey he will pop bloons IN SLOW FORWARD motion when shuriken is still popping.

Double Fire Glitch

 * If upgrading a tower when it is doing the pre-firing animation, it will have its attack interrupted, and will instead fire two upgraded shots afterwards.

Ability Stutter Glitch

 * If Active Ability is at rank 5 of higher, using an ability will cause towers to 'stutter' (even Banana Farms), resetting their attack cooldown. This makes supply drop farming a lot less effective, unless you have a couple Absolute Zero abilities to freeze the bloons when the stutter happens. This is demonstrated here: https://www.youtube.com/watch?v=8u2caspj7GY

Ninja Seeking Bug

 * Ninja monkeys with the Seeking Shuriken upgrade can/will only target the closest bloon, regardless of targeting preference. If another bloon passes them, they will face the first bloon, and then throw towards the nearest. The Shuriken SHOULD target the bloon the monkey is facing, and then bounce TO the nearest, but it does not. This happens in BTD Battles as well.

Damaged Unbuilt Tower Bug

 * If a building is in construction, and then your buildings are damaged in an MvM attack, sometimes the in-construction tower will get damaged.
 * If this happens, the damage time is added to the construction time. But sometimes, the timer will stop permanently, and the building can only be finished with bloonstones.

Upgrade Bug

 * If you have an upgrade building in research progress, you can still access it by clicking another research building and selecting the other building from it. Most likely intentional.

Building Disappeared Bug

 * Extremely rare, but sometimes you can place a building on one of four super monkey villa spaces. If you move the villa, the building will either disappear or you can't put the villa in its original spot. Also, when moving the villa, the tile where the building disappeared will have a green-striped pattern. The building will reappear when the player moves the villa off of the spot and reloads the game.

Defended Attack Bug

 * Rarely, when a player defends your attack in Monkey vs. Monkey, the message continues to pop up, and you lose honor every time it does. This causes your honor to eventually reach 0. However, this is fixed by reloading the game.

Pillage it all!

 * When winning an attack, you can get double, triple, or even quadruple the original pillage amount of city cash. The additional money will not be shown at first, but after refreshing the page the value will update.

MOAB Class Bloon Glitch

 * Sometimes, when you are playing a track with multiple paths, MOAB Class bloons (especially BFBs and ZOMGs) can start on one path, disappear, and reappear at the beginning of the other path.

Contested Territory Reward Bug

 * If the CT panel is open when the milestone/occupation event ends, the next event will start shortly before the map changes, giving any possible rewards for the new event as well as the previous one.
 * For example, if you held CT for 1 day while the milestone event was on, you will also get the 1 day occupation reward when it starts, along with all the previous occupation rewards. If you go for the 2 day occupation now, you have to hold the CT for 2 more days since the capture times are reset when the map changes. You also can't recollect any rewards you've already gotten by hitting the desired hold times.

Contested Territory Fail glitch

 * Sometimes if you win a CT, you will not be holding the territory, even if you are first mainly after one day. It could also happen to other winning opponents.
 * Sometimes, your total time you held the territory will reset. This is fixed by refreshing the page.
 * Ninja Kiwi said it is by server failure saying that the game may not remember the process of CT and may say someone else took it.

Infinite Cash For CT
If you win a CT, wait a while. When holding, the farm cash exceeds into hundred millions of cash after a while. Abusing the glitch can get your account banned.

Sentry range bug

 * For some reason, if you click on a sentry that doesn't attack any bloons in its duration and the time expires while the stats for the sentry are still shown, its range will still be on the screen. clicking on one of the targeting options will cause all four buttons to disappear.

Sentry on track or water bug

 * Boomerang Monkey 2-0.pnggely, when the player buys at least a 1/0 Engineer, and if there are towers that fill the 1/0 Engineer's range and when there little to no space for sentries to randomly spawn within the Engineer's range, sentries will start spawning on the pathway where bloons travel or if the Engineer's range covers water then sentries can start spawning there too.

Incorrect Music Glitch

 * Sometimes when you play a contested territory (possibly any tile) in your second city, you'll go back to your city noticing it is playing the tune from the 1st city.

Red Hot Spikes Glitch

 * When you buy red hot spikes with fewer than 5, they are free. Possibly intentional.

Lose when you haven't glitch

 * If you click on monkey boost when you have fewer then 5 and press cancel, it will say that you ran out of lives, even though you still have lives. While it's saying that you've ran out of lives, and you really do run out of lives, the screen will get darker. Exit and re-enter the same level and the screen will still be dark. It won't let you place anything, so you'll have to reload the game.

No Victory Bug

 * Sometimes after capturing a tile, it has the appearance of a non-captured tile in your city until you move your mouse off of it.

I Lost All My NK Coins Bug

 * Occasionally the game will bug out, and not allow you to spend NK coins earned from spinning the wheel, or from purchasing. If the page is refreshed any Premium Buildings will have been purchased, however (Only Monkey Knowledge Packs confirmed) will disappear, and your NK coins will not be given back to you. If this happens the only solution is to contact Ninja Kiwi (via support@ninjakiwi.com). They have found this bug and is confirmed known; they are working on it currently and contacting them will refund your NK coins.

Game Disconnect Bug

 * When you collect money/bloontonium from a specific building the game may give a server error causing you to reload the game. After that you may duplicate or lose all the resources. The errors should stop after around an hour.
 * Moving that Buidling will error the game forces you to reload and the building will be duplicated.
 * The game may also error when spending bloonstones, which in that case you lose the bloonstones.
 * The game may error when you claim a tile. You might lose the tile and all rewards. If that does not happen then you will lose the money gained from the tile.
 * The game may error just randomly after a while.
 * Descriptively, certain occasions can pop up an error that says Server Error with a monkey holding a cord. Retry will not do anything and after a few attempts the monkey will be electrocuted and the error message says you need to reset the game. After that, you are sent to the title screen. Clicking play will make loading stuck on "Connecting to Server..." You are then forced to refresh the page.

Temple Misdirection

 * When attacking relatively weak bloons such as blacks, whites, or zebras, a Temple of the Monkey God may very briefly fire directly to the left, even if there are no bloons in that direction. Influence of a Monkey Village does not affect this glitch. This can happen with any tower.

Flash Crash of Death

 * Usually caused by a old or laggy computer or by an outdated processor, if you win a tile and then flash crashes, you will not win the tile because the game did not have time to save your data. The only workaround is to use a high end computer or upgrade your processor as flash will less likely to crash on a better computer or processor.

Re-winnable Missions

 * Sometimes, when transferring from your first city to your second, two messages will appear, one after another. The first says that you have completed the Longer Darts mission (which requires research of Long range Darts for the Dart Monkey), and the second says you have completed the Better Boomerangs mission (which requires research of Multi Target for the Boomerang Thrower). You receive the indicated rewards for the two missions if you click the continue button. This glitch only occurs if you have already completed the missions by doing the required research.

Ultra-Temple Glitch

 * Occasionally, when sacrificing a 4/x Mortar Monkey, a Temple of the Monkey God will become incredibly powerful, being able to completely destroy even ZOMG's before they fully appear. This makes it impossible for anything to get past the tower (unless in a high round on Contested Territory). While it might be said that sacrificing a 4/x Mortar Monkey would make each shot from the Temple pop five layers, the fact that it only happens every so often identifies it as a glitch, no matter if the Mortar super-powers the Temple or the Temple fails to absorb the ability of the Mortar.

Replaced Building Bug

 * Rarely, when loading a city, one building might be replaced by another building. The screenshot shows a second Bloon Research Lab that took the place of a Dart Monkey Hall.

Repeating Quests

 * Very rarely, the game can bug out when loading a city, and all of the quests will reset and can be re-earned. Some of them will be completed immediately, like having a certain researched complete, but others will require you to complete a tile to earn them again. All of the money and XP are earned again like normal and can drastically boost your cash and experience. The screenshot to the right shows some of the quests that returned.

Building Duplication Crash

 * Rarely, when a building is moved into a large area of space, a duplicate of itself will appear next to it. It doesn't affect gameplay but the duplicate cannot be moved. To fix this, demolish this building then the game crashes. When the player goes back into the game, everything goes back to normal except that the demolished building is still gone. It is unknown if this can happen in other devices as this happened on the iPad.

Upgrade Crash

 * Upgrading towers can sometimes result in a game crash. It can only happen in the SD version of the game.

Defending Against Contested Territory

 * When there is a MvM attack and you defend against it and go to an uncaptured Contested Territory the play button instead of saying "Play" it will say "Defend" and will display the shield.

DDT can fit

 * A DDT can be sucked into a bloon trap. If you collect it, you will mainly collect around 33000 cash.

Repairing upgrade

 * In Submarine alliance if you tap the broken sub and tap another tower in the upgrade button It will display repair the sub.

Can't Stop The Ice Bloons!

 * Ice towers under the effect of a x/3 monkey village can pop anything, however ice and zebra bloons are still immune to being frozen unless the snap freeze upgrade changes the ice into pinks. This also means that snap freeze turns rainbow bloons into zebras, so they cannot be frozen either. This bug is not present in any other game and ruins the late game viability the ice tower.

Contested Territory Fail glitch 2

 * This is very similar to the same glitch on the flash version, but now it instead restart them back to round 0. Milestones are still saved.

No Restrictions, No Favors

 * Even on tiles they are not allowed, the restricted towers can still be used. However, all favored towers will then not be favored. This glitch has been out since the first release. It happens when you enter the track in the My Tracks menu.

Boosts floating out of nowhere

 * First, open your towers in a tile. Then, put your device to sleep. Wake it up and if you press resume then you can see the boosts floating.

Incorrectly Rewarded

 * If you have a complete a tile by beating a MOAB-class bloons in quest, and you successfully defend the tile that was the MOAB-class bloon that matches the quest, you will complete the quest even though it is just a MvM attack and you do not capture the tile.

Bloons not appearing

 * Some lead or DDT tiles may not show lead or DDT bloons. If it happens on a lead tile, it is replaced by zebras.
 * Conversely, DDTs can appear on tiles that are MOAB/BFB Packs.

Cookoo Bloon Strategies

 * When accessing track replays, when choosing bloon strategy, you will most likely get a different Bloon Strategy then the one you wanted to do. (e.g. Camo Craziness does Hard and Heavy instead)
 * With Cash Starve, MOAB/BFB Pack, and DDT tiles, it is possible to have combined bloon strategies, like Cluster Chaos combined with Cash Starve.

Flying sentries

 * An easily reproducible glitch, monkey engineers may build sentries on any terrain. However they prefer to build sentries on build-able ground, but if there is no space (due to filling the nearby area with monkeys) a sentry will spawn wherever it can on the map within the engineer's range. This also happens in BTD5, BTD5 Mobile, BMC, BTD Battles, and BTD Battles Mobile.

Broken Bloon Trap Glitch

 * After a Bloon Trap is full, it still has its opening animation and does not close. After tapping it, you get the money and it turns into a ghost trap. It is not there, but you can still see it animating. It gets destroyed some time later. It can make you look like one Engineer has 10 or more Bloon Traps, when in reality, it only has the usual one. This is because each frame stacks on top of each other. This only happens in the SD version; it does not happen in the HD version.

Hyper-sonic Spike-O-Pult Glitch

 * To accomplish this glitch, the player needs a 2/0 Dart Monkey and a 0/4 Dart Monkey. Then, the player should activate the Super Monkey Fan Club Ability and upgrade the 2/0 Dart Monkey into a Spike-o-Pult, but it is only hyper-sonic for 10 seconds. This also works on Juggernaut as well, allowing the player to easily obliterate ceramics and MOAB-class Bloons.

Challenge Saving Bug (Minor)

 * It is possible to save in Challenges, however, it's only before the player starts the first round, which is rather useless.

More than max glitch

 * In the July 18th 2012 challenge, if the player has reached the limit of one tower type, and sell a different one, the player can buy another one of that one, but once the player buys it, it will be locked again.

Unlimited NK Coins/MM Glitch

 * When the player purchases MM with NK coins, the player won't lose MM when they buy Special Agents, nor NK coins. See: Here,or here..

Missing Menu Bug

 * On the intro screen in BTD5, right click, then click on the play button. The play button screen will still be there, yet, if the player clicks where any of the menus would be (e.g.: special agents), that menu will be opened.

Life Bug

 * This bug can happen on almost everything the player does on BTD5. The first cases of it happened on the March 11, 2012 Daily Challenge, and the Wizard Lord Special Mission. The glitch is when the player loses all of their lives, the Game Over screen will not appear and the player can still play. However, the player's towers cannot attack and there will be no "Go button" as if the player had lost. (this was never patched on Deluxe. Sorry.)

10 Bug

 * This rarely occurs, once the player loads a save game with a Portable Lake with Monkey Buccaneers on top of it, it will show the number ten with a hour glass next to it, as if the player is on the special mission, Short-Lived.

Alarm Bug

 * If The player clicks the quit button, run out of lives, then click yes, an alarm will sound until the player plays, where the player gets a Game Over. This also happens in the Wizard Lord special mission when the player runs out of towers, except there is no escape from it other than closing their browser.

Track 2 Bug

 * If the player plays a beginner track on BTD4 and save, and when the player goes to the expansion, it will take the player to track 2 although Ninja Kiwi seems to know this as when the player does this there is a message saying that the save is from the original game and results may be unexpected.

Bug when logging into the game

 * The game has a system where the player can only play right into Ninja Kiwi. But in an update, double monkey money, the game itself did not identify the site of origin. Even if the player is on Ninja Kiwi, it gives the message "play now on Ninja Kiwi".

Special Abilities Bug

 * When a tower with an ability is sacrificed to a temple, the ability will stay, though it is supposed to disappear. The ability can't be used.

Description bug

 * Bug 1: In the MOAB Madness special mission, after winning the challenge, a comment will appear (it says Easy peasy.), which is the default comment for Round 2, and that's ironic, because there is no Round 2 in the MOAB Madness special mission. However, an update (April 2, 2013) made no pre-round messages appearing (even if tips are turned on) in Daily Challenges, nor Special Missions.
 * Bug 2: When opening a Daily Challenge (or Special Mission), when starting the challenge or mission, the default comment for round 1 (the welcome message) appears instead of the description of the challenge or mission. This was fixed on the same April 2, 2013 update.

Hotkey Abuse Bug

 * This is a glitch which is similar to the tower placement glitch except the player can use the hotkey of a locked tower.

Negative XP Bug

 * In BTD5 Deluxe, when it was first released, Ice Tower's XP was bugged and had negative values causing it to never level up. Fixed two days after release.

Money Losing bug

 * In BTD5, when the player presses the hotkey (, for the left path and . for the right path) for upgrading on a path where there is an upgrade locked, the player will lose money (the cost of the upgrade) for nothing and the tower will not be upgraded. It will also increase the selling price. Fixed in Feb 20, 2013.

Fast Upgrade Glitch

 * In BTD5 Deluxe, when playing the Fast Upgrades special mission, it was possible for a tower to upgrade to an upgrade you haven't unlocked yet. This was patched on August 26, 2013.

Saving bug
When the player tries to play a Daily Challenge or a Special Mission, the game will take the player to the previously saved game instead of the challenge or mission. This was fixed on April 2, 2013.
 * This bug seems to be a variant of Deflation Saving bug.

Giant Lock Bug

 * After the Double Monkey Money update in December 19, 2012, before starting BTD5, a giant lock flashing purple and green will appear, and in a second, the player starts the game quicker than usual. This bug was fixed in January 8, 2013, right when the Double Monkey Money event ended. This may be a holiday surprise for the players.

0 after buying Special Agents

 * When the player buys more than 1 special agent a time, the player loses all of their monkey money, and the player will not get the agent. The player gets back the Monkey Money only when earning them by completing a game.

Hydra Rocket Pods Bug

 * The 2/3 Dartling Gun shots don't explode, but just pierce through bloons.

Opening Title SFX Bug

 * There was a bug in which the sound effects in the opening title wouldn't play. This was fixed on Thursday, June 14, 2012. In the selfsame update, Specialty Buildings were added.

Premium Bug

 * This was a glitch where if the player left clicks at the edge of the premium upgrade, the player will activate the upgrade for free. This glitch was patched 2 weeks after the release of the game.

Tack Awesomizer Bug

 * Road Spikes do 13 pops instead of 22 with Tack Awesomizer.

Pro Tribal Turtle Bug

 * Tribal Turtle Pros cannot be placed on water.

Monkey Ace Bug 2

 * 3/0 Aces can target Camo Bloons but it cannot pop them. 4/1 aces can drop pineapples at the Camo Bloons, but the pineapples can't pop them.

Rank Skip Bug

 * Upon reaching Rank 98, your rank is skipped to 134.

M.O.A.B. and B.F.B. Mortar Tower Glitch

 * In version 3.2 for Bloons TD 4 iPod/iPhone, the Mortar Tower could kill M.O.A.B.s and B.F.B.s in one shot, making it very easy to beat all 250 Rounds. It does not effect the damage on any other bloon, despite this. Fixed in version 3.2.1.

Save Bug

 * (Only works in BTD5) Complete a difficulty and then click on the save button really rapidly before the message says "Congrats! You beat this track on _____!". Then when it has saved, the player must exit out then load it again. Once the player passed this level, the player can save in Freeplay Mode.

Tower Sell Bug

 * When the player sells a tower, it doesn't go away, and it just gives the player money. This occurs when a player opens their BTD4 save file when playing BTD4 Expansion (whether or not this is for the first time isn't confirmed).

Track Jump Glitch

 * In BTD5, Bloontonium Lab, Snake River, and Mount Magma suffer a glitch which causes bloons to skip parts of the track. Click here to find out more.

Fast Sandbox Bug

 * When Fast Track Mode is turned on, and you go into sandbox mode, you will only have the Fast Track Cash even though it looks like you still have infinite.

Challenge Bug

 * After playing a challenge in BTD4 (such as the one to defeat 50 M.O.A.B.s in one round), placed some towers but didn't yet start the game before quitting, and then when the player goes on it again and click "Load Game", the player will get a lot of money, and the towers the player placed.

Treasure Chest Glitch

 * When the player has already opened the Treasure Chest in BTD5, it will be open and have a small 999 in it. When the player clicks, it will still give Monkey Money. However, then the player can't get Monkey Money the next day. This is not completely a glitch, as this does occur at the time it is meant to happen.

Black Screen Bug

 * In BTD Battles, if the player loses, their screen will turn black after the player has won a new battle.

News Table Bug

 * Sometimes, when the player enters BTD5, the News Table is bugged, and the player can't view any news, or the BTD5 mobile table. It is unknown why that happens.

Banana Farm On Deflation Bug

 * It is possible to get a Banana Farm by clicking on the very edge of the button of the tower. It also gives the player money. However, this was patched and it is no longer possible.
 * Something similar could be done with the Monkey Engineer via the Bloon Trap upgrade on Bloons TD 5 iOS. However, this was also patched.

Road Spikes Bug (minor)

 * When spamming road spikes in BTD5 iOS, and the player ends up with less than $30, the player could buy their last pile of Road Spikes for less than $30. Fixed in version 2.1

Stupid Mortar Glitch

 * Those pesky mortars can't aim right: When the player targets an area in BTD Battles, the mortar aims somewhere else, although the shells still explode at the target.

Disconnection Bug

 * After you and your opponent choose towers on Bloons Tower Defense Battles iOS, one player will see the waiting for opponent screen, while the other one is already playing round 1. After Round 1, the game doesn't start Round 2. The player who first played Round 1 will get infinite money in several seconds.

Banana Farm Flash Crash bug

 * In Bloons TD Battles, when Banana Farms are used (even if upgraded to Monkey Banks), a flash crash is likely to occur in a part of the game. There's no specific round where this happens - it's completely casual. It's unknown when this glitch started to occur - first reports of this bug were in October 24, 2013 and the bug was patched on January 14, 2014.

Unnecessary Lag bug

 * Neva-Miss Targeting causes lag for no reason when it starts to shoot.

Bullet/Slo-Mo Matrix speed bug

 * In Bloons TD Battles, as of October 14, 2013, there are added codes for an anti-hack system, which never got implemented until a few months later, adding some memory. These codes cause lag for no reason in at least 20-40% of the games. The lag can cause the game to be slower from 1.5x slower to 8x slower. Sometimes the lag starts only in late rounds, but it's much worse than the normal lag. Computers' speed seem to affect this. Example of unnecessary lag here.

Earlier is Later bug

 * In the February 23, 2013 challenge (I Spy with My Eye), the description says the challenge ends at round 70, but when the player starts the challenge, it says 85. It is changed when the player reaches round 2. It will also happen with other challenges.

Round/Sandbox Mode

 * In Bloons TD Battles, there was a bug that activated when typing in a secret code.

Towers Placeable Everywhere
If the player hovers their cursor over a spot where the player can place a tower when the player has a tower selected, and right click on that spot, and then while the right-click menu is shown, click anywhere and the player can place that tower anywhere. (Patched in v1.12 BTD4 original and v1.18 expansion)

Black Bloon Sharp Shuriken Bug

 * Sometimes a discoloration of the the Sharp Shuriken upgrade for the bloon to be black and not red. It was later patched.

Spike Factory shooting Spiked Balls without upgrades

 * In Bloons Monkey City, when the Non-stop mode update was first added, a major glitch was introduced where, if you buy a spike factory, instead of acting like a normal 0-0 spike factory, acts like a 3-0 spike factory without upgrading. This was quite game breaking as this allowed Ceramic and M.O.A.B tiles to be beaten at very early city levels with almost no trouble. This is demonstrated in the following video: https://www.youtube.com/watch?v=hyCR_cGFDQg
 * Shortly after Junior Monkey made the video, it has been patched, as of December 1, 2014.

Road Item Crash

 * This glitch was bought up when Bloons Monkey City Mobile first released. This is an issue that's caused when a player tried to place road spikes or pineapples when they don't have enough money for them. This is because the game does not know if you have enough money or not so it won't exit. This will cause the game to crash by the time you tap anywhere. Fixed in version 1.1

Hole by Selling bug

 * In mobile versions of BTD5, and in the Protect Monkey Town special mission, it is possible to sell the Monkey Town for $0, leaving a hole in the middle. The player still loses lives if bloons will go in the hole. The same goes for the Wizard Lord, and if this happens, the player automatically loses when a tower needs to be sacrificed. Fixed in version 2.1

Sextuplet Darts

 * When a/there are Dart Monkey(s) (is) under the effect of Super Monkey Fan Club, it simultaneously throws darts at a hypersonic rate and it also throws Triple Darts. Fixed in version 2.0

Banana farmer out of control bug

 * Sometimes when a bloon trap is in the range of the banana farmer, the bloon trap will fly towards the banana farmer. However, you only get $40/$60/$400/$600, not the bloon trap cash. Fixed in version 2.1

Repeated Winning Bug

 * When you win a raid, it keeps popping up that your won the raid and gives you free cash, honor, and possibly achievements. The honor will go back to normal after reloading the page but the cash doesn't disappear. Also, in your battle log, it might show 10/7 raids won or more raids won than raids done.

Temple Trap glitch

 * Similar to Spectre stole ground zero's ability glitch. activate the glitch with a super monkey. upgrade to temple of the monkey god with no super monkey on the screen. The temple will appear for a split second, sacrificing all towers around it like an average temple, then disappear.

Spectre stole Ground Zero's ability

 * If you buy a tower, make their white outlines appear then click, upgrade to 1/3 or 3/1, sell, and click4 4 Monkey Ace.png very rapidly. It will show the upgrade section where you can upgrade to 4/4. Only Monkey Ace is allowed to still attack, every tower else is gone forever, so you can have a Spectre with Ground Zero combined. Through still every other tower being disappeared, they can still be upgraded to their ability, but the tower is still not there, being extremely useful for Daily Challenges where they restrict the number of towers with abilities.
 * You can get an unlimited amount of monkey aces with this glitch.

Chinook Glitch

 * Temples cannot be moved by Chinooks normally, but by using the moving ability, you can move a sun god WHILE it is upgrading to a temple by moving the sun god then getting the upgrade to temple while the Heli-pilot is still going towards the sun god, making temples possible to be very close together. Might want fast hands for this glitch. You can possibly counter the temple bug this way, as you can place a temple on top of a pontoon and it won't disappear with this glitch.

Super Overclock Glitch

 * Overclock can stack with most towers, allowing them to become extremely powerful. In version v150831 however, this has been patched.

No Money Glitch

 * When you use up all your money on the tutorial and it asks you to upgrade your dart monkey beacause of camos then you will not get extra money and you cannot finish the tutorial. Now, the game gives you money if you don't have enough.

Where is my free boomerang?

 * On the 1.1 update of BMCM, you will not get a free Boomerang Thrower in Wattle Trees, even at the start and after three rounds. This was not fixed until the 1.3 update.