Since a lot of people have been encountering all manner of bugs and glitches in Luigi's Mansion Dark Moon, I thought it was time we had an official list topic with all of them in it.
ScareScraper Glitches
Key Glitch
Sometimes, a key won't spawn in a room that's meant to have one (according to the map). It's rumoured that this is because the key is actually in a different room and the map itself is what's glitched.
Fall through Floor Glitch
If you fall through a Sneaker boss generated portal, it's possible you'll come out halfway in the floor in the room you land, at which point Luigi will fall through and appear like his shadow is on the ceiling. You don't lose health if this happens thankfully enough.
Boss Doesn't Die Glitch
It's possible to kill a boss and have the game not consider it as dead. This usually happens if you catch a Sneaker boss and fall through a portal at the same time.
You can then sometimes cause the fight to end by returning to the boss room.
On Top of Furniture
If you fall through a Sneaker boss portal, it's possible to end up landing on top of a solid object, at which point Luigi will either slide off in a ridiculous pose or get stuck on top.
Multiple Boss Glitch
It's apparently possible to have another boss spawn during a boss battle unintentionally, causing all kinds of grief (like having to fight a Gobber boss and Slammer/Sneakers bosses at the same time). The level still ends when the first boss is caught.
Red Coin Sound Glitch
Sometimes the red coin music will echo for unknown reasons during the Red Coin Hunt. It's hypothesised that this is due to Luigi making a sound during the hunt/when it begins and causing the sound channel to screw up.
Map Spawn
(from Mario Wiki:
In Rush Mode, sometimes if a player enters a room with a map item in it and defeats the last ghost in that room and falls in a carpet trap while the ghost is still going in the Poltergust nozzle, a huge amount of maps will constantly spawn from the nozzle and may cause the game to lag until the player is freed from the carpet trap.
Red Coin Success/Failure Error Glitch
If Luigi gets the last red coin after time runs out, it's possible for the game to play his 'failure' animation afterwards despite him having gotten all the coins and the slot machine giving him an item. It's also conversely possible to have the game count this as a failure despite technically succeeding.
Ghost Red Coin Glitch
According to reports, it's apparently possible to have a red coin spawn in the red coin hunt but not act as solid, hence Luigi/Luigis simply walk or run straight through it. This causes the hunt to become unwinnable by mistake.
Stuck in Closet
It's possible to have two players run into a closet and end up with one stuck in there until time runs out/the floor ends, unable to do anything.
Stuck Ghost Glitch
It's also possible to have a ghost get stuck halfway in the Poltergust nozzle (with part of its head sticking out the end). No one knows why, but it's a harmless glitch.
Stuck in Furniture Glitch
If a player uses the Dark Light when inside an invisible object, it's possible the object will materialise around them (it usually stays transparent/non existent until they leave the spot) and trap them until the floor ends.
5th Red Coin Glitch
A 5th red coin may spawn. Has no effect though, game still ends when four coins are collected.
Luigi Circle Glitch
This happened to someone online apparently:
http://www.youtube.com/watch?v=CO1T3OjhgoU&feature=youtu.be
One poor Luigi got stuck flying round in a circle as if pulled by an invisible ghost or speedboat.
Unresponsive Room Glitch
Described by Servbot here, sometimes it seems rooms in the ScareScraper just become completely unresponsive to everything. The poltergust can't grab carpets to help people from traps, the Dark Light couldn't reveal hidden furniture, And various other things.
http://nintendo3dscommunity.com/topic/11257-oh-come-on-luigis-mansion-2-related/?p=110474
Other Glitches
Toad Stuck Glitch
In mission 2 of Treacherous Mansion (Double Trouble), sometimes one or more of the Toads will get 'stuck' on the staircase. They'll then appear from the sky a second or so later and act as normal afterwards.
Stuck in Fountain Glitch
It's also apparently possible to be stuck JUST where the fountain in Treacherous Mansion materialises, forcing you to have to restart the mission or quit.
Floating Object Glitch
After a whole bunch of dollar notes appear (like from a stash), it's possible that one or more will get stuck in mid air and not come down. Luigi can still use the Poltergust to collect 'stuck' notes though, so it's merely a visual glitch.
It's also possible that things like fake mustaches and glasses from Greenies will get stuck in mid air too, like this picture:
Locked out Glitch
By moving an object (like a bucket or log) so its on the switch in the Treacherous Mansion's Nautical Exhibit and having a ghost hit it, it's possible to have the object fly off the switch AFTER you enter the door behind the ship's wheel. Once this happens you're stuck and the mission is unwinnable.
Trapped in Floor Glitch
Also in Treacherous Mansion, you can land on an object in the Dark Ages Exhibit by using a Balloon Fruit from the study and bringing it through the teleporter. This can cause Luigi to get teleported into the 1st floor/ceiling and be trapped in a position where he can't move and the screen is always violently shaking, Once this occurs, you have to quit/restart the mission.
Here's a video:
http://www.youtube.com/watch?v=U5WW23w1obA
AI Breaker Glitch
Ghost AI cannot cope with the top floors in the four main exhibits of Treacherous Mansion. If Luigi goes up there with a Balloon Fruit when ghosts are in the room, these ghosts will either appear 'stuck' to the non existent ceiling and completely harmless, or will literally end up taunting or attacking a wall non stop.
Bucket inside machine
In the first mission of Haunted Towers, it's possible that the bucket the Greenie is wearing in the final room (with the water supply) will get stuck inside the machinery, making it impossible to use to complete the mission.
Stuck Boo Glitch
Boos can also apparently can get stuck outside walls in solid form if you use the Dark Light on them then with bad timing.
Frozen Ghost Glitch
If you get a gem and catch a Greenie at the same time, the Greenie might end up frozen in place forever more, completely unable to be interacted with.
Stuck Behind Kettle Glitch
In the Deep Hall in the Secret Mine, you can be pushed behind the wall near the kettle if you grab a gem from a ghost with the right timing.
Dark Moon Piece No Spawn Glitch
You can apparently end up not having the Dark Moon piece spawn after defeating a Possessor boss, forcing you to restart or quit the mission.
Flash Light Glitch
It's also apparently possible the Strobulb will just stop working. As in, makes a sound/appears, but doesn't stun ghosts. Mission restart time!
Audio Glitch
Sometimes all sound effects just cut out. Like in this video:
http://www.youtube.com/watch?v=xa5RZAfatUQ
Lost the Key Glitch
In the second mission of the Secret Mine, it's possible to literally drop the key over the edge of the world and never be able to get it back. Like this:
http://www.youtube.com/watch?v=IvLgRIs7QD4
Never respawns too.
Inaccessible Treasure Glitch
In all modes, it's possible for money to end up falling through a wall and becoming uncollectable.
Camera Pull Back Glitch
When going through a door, sometimes the camera will end up pulled back too far, showing the black void behind the entrance door. This glitch fixes itself after a second or so and is merely aesthetic.
Both the above glitches happen in both the adventure mode and the ScareScraper/Thrill Tower.
So if you know of any more glitches in the game (whether through watching videos of them online or experiencing them yourself), post them below and they'll be added.
ScareScraper Glitches
Key Glitch
Sometimes, a key won't spawn in a room that's meant to have one (according to the map). It's rumoured that this is because the key is actually in a different room and the map itself is what's glitched.
Fall through Floor Glitch
If you fall through a Sneaker boss generated portal, it's possible you'll come out halfway in the floor in the room you land, at which point Luigi will fall through and appear like his shadow is on the ceiling. You don't lose health if this happens thankfully enough.
Boss Doesn't Die Glitch
It's possible to kill a boss and have the game not consider it as dead. This usually happens if you catch a Sneaker boss and fall through a portal at the same time.
You can then sometimes cause the fight to end by returning to the boss room.
On Top of Furniture
If you fall through a Sneaker boss portal, it's possible to end up landing on top of a solid object, at which point Luigi will either slide off in a ridiculous pose or get stuck on top.
Multiple Boss Glitch
It's apparently possible to have another boss spawn during a boss battle unintentionally, causing all kinds of grief (like having to fight a Gobber boss and Slammer/Sneakers bosses at the same time). The level still ends when the first boss is caught.
Red Coin Sound Glitch
Sometimes the red coin music will echo for unknown reasons during the Red Coin Hunt. It's hypothesised that this is due to Luigi making a sound during the hunt/when it begins and causing the sound channel to screw up.
Map Spawn
(from Mario Wiki:
In Rush Mode, sometimes if a player enters a room with a map item in it and defeats the last ghost in that room and falls in a carpet trap while the ghost is still going in the Poltergust nozzle, a huge amount of maps will constantly spawn from the nozzle and may cause the game to lag until the player is freed from the carpet trap.
Red Coin Success/Failure Error Glitch
If Luigi gets the last red coin after time runs out, it's possible for the game to play his 'failure' animation afterwards despite him having gotten all the coins and the slot machine giving him an item. It's also conversely possible to have the game count this as a failure despite technically succeeding.
Ghost Red Coin Glitch
According to reports, it's apparently possible to have a red coin spawn in the red coin hunt but not act as solid, hence Luigi/Luigis simply walk or run straight through it. This causes the hunt to become unwinnable by mistake.
Stuck in Closet
It's possible to have two players run into a closet and end up with one stuck in there until time runs out/the floor ends, unable to do anything.
Stuck Ghost Glitch
It's also possible to have a ghost get stuck halfway in the Poltergust nozzle (with part of its head sticking out the end). No one knows why, but it's a harmless glitch.
Stuck in Furniture Glitch
If a player uses the Dark Light when inside an invisible object, it's possible the object will materialise around them (it usually stays transparent/non existent until they leave the spot) and trap them until the floor ends.
5th Red Coin Glitch
A 5th red coin may spawn. Has no effect though, game still ends when four coins are collected.
Luigi Circle Glitch
This happened to someone online apparently:
http://www.youtube.com/watch?v=CO1T3OjhgoU&feature=youtu.be
One poor Luigi got stuck flying round in a circle as if pulled by an invisible ghost or speedboat.
Unresponsive Room Glitch
Described by Servbot here, sometimes it seems rooms in the ScareScraper just become completely unresponsive to everything. The poltergust can't grab carpets to help people from traps, the Dark Light couldn't reveal hidden furniture, And various other things.
http://nintendo3dscommunity.com/topic/11257-oh-come-on-luigis-mansion-2-related/?p=110474
Other Glitches
Toad Stuck Glitch
In mission 2 of Treacherous Mansion (Double Trouble), sometimes one or more of the Toads will get 'stuck' on the staircase. They'll then appear from the sky a second or so later and act as normal afterwards.
Stuck in Fountain Glitch
It's also apparently possible to be stuck JUST where the fountain in Treacherous Mansion materialises, forcing you to have to restart the mission or quit.
Floating Object Glitch
After a whole bunch of dollar notes appear (like from a stash), it's possible that one or more will get stuck in mid air and not come down. Luigi can still use the Poltergust to collect 'stuck' notes though, so it's merely a visual glitch.
It's also possible that things like fake mustaches and glasses from Greenies will get stuck in mid air too, like this picture:
Locked out Glitch
By moving an object (like a bucket or log) so its on the switch in the Treacherous Mansion's Nautical Exhibit and having a ghost hit it, it's possible to have the object fly off the switch AFTER you enter the door behind the ship's wheel. Once this happens you're stuck and the mission is unwinnable.
Trapped in Floor Glitch
Also in Treacherous Mansion, you can land on an object in the Dark Ages Exhibit by using a Balloon Fruit from the study and bringing it through the teleporter. This can cause Luigi to get teleported into the 1st floor/ceiling and be trapped in a position where he can't move and the screen is always violently shaking, Once this occurs, you have to quit/restart the mission.
Here's a video:
http://www.youtube.com/watch?v=U5WW23w1obA
AI Breaker Glitch
Ghost AI cannot cope with the top floors in the four main exhibits of Treacherous Mansion. If Luigi goes up there with a Balloon Fruit when ghosts are in the room, these ghosts will either appear 'stuck' to the non existent ceiling and completely harmless, or will literally end up taunting or attacking a wall non stop.
Bucket inside machine
In the first mission of Haunted Towers, it's possible that the bucket the Greenie is wearing in the final room (with the water supply) will get stuck inside the machinery, making it impossible to use to complete the mission.
Stuck Boo Glitch
Boos can also apparently can get stuck outside walls in solid form if you use the Dark Light on them then with bad timing.
Frozen Ghost Glitch
If you get a gem and catch a Greenie at the same time, the Greenie might end up frozen in place forever more, completely unable to be interacted with.
Stuck Behind Kettle Glitch
In the Deep Hall in the Secret Mine, you can be pushed behind the wall near the kettle if you grab a gem from a ghost with the right timing.
Dark Moon Piece No Spawn Glitch
You can apparently end up not having the Dark Moon piece spawn after defeating a Possessor boss, forcing you to restart or quit the mission.
Flash Light Glitch
It's also apparently possible the Strobulb will just stop working. As in, makes a sound/appears, but doesn't stun ghosts. Mission restart time!
Audio Glitch
Sometimes all sound effects just cut out. Like in this video:
http://www.youtube.com/watch?v=xa5RZAfatUQ
Lost the Key Glitch
In the second mission of the Secret Mine, it's possible to literally drop the key over the edge of the world and never be able to get it back. Like this:
http://www.youtube.com/watch?v=IvLgRIs7QD4
Never respawns too.
Inaccessible Treasure Glitch
In all modes, it's possible for money to end up falling through a wall and becoming uncollectable.
Camera Pull Back Glitch
When going through a door, sometimes the camera will end up pulled back too far, showing the black void behind the entrance door. This glitch fixes itself after a second or so and is merely aesthetic.
Both the above glitches happen in both the adventure mode and the ScareScraper/Thrill Tower.
So if you know of any more glitches in the game (whether through watching videos of them online or experiencing them yourself), post them below and they'll be added.