The game will sometimes produce a .txt file containing an error message onto the desktop whenever the game is closed down. A similar error message is also produced when the game actually does crash.
Sometimes a specific chunk will constantly revert. Water will not duplicate in these chunks if it is flowing, and water tends to linger much like lava when the source is removed.
You are unable to directly swap items in your inventory when the two items are same. This is important if you would like to swap the same item type with two different durability values.
Sometimes you can see through everything; this randomly happens on all games on all platforms. Toggling the fog distance will change everything back to normal (Default key is F).
Occasionally, picked up items will not appear in the inventory
If you die while viewing your inventory, your character will fall out of the box and will be rotated sideways.
Sometimes, the game may reset the seed that the map generates from. This is a result of tweaks of the seed and terrain generation code that are regular parts of the game's updates.
When sand or gravel is generated above a cave (or any opening), it will float until a space by it is modified in any way.
The addition of sandstone has 'fixed' the floating sand by naturally providing support.
Holding the Sneaking button then pressing the key to pull up the menu and quitting will result in being one block lower when the save is opened again.
The red glow featured at sunset and sunrise is normally a gradient. Pulling up the player's inventory will cause the gradient to solidify along a sharp boundary.
Occasionally, when saving the game and reloading, you will fall through the block you were standing on.
A bug exists where the game may refuse to remember custom controls after updating (not to a specific version - just updating in general). This is caused by one of the values in Minecraft's "options.txt" file being unset, usually the "lastServer" field - attempting to connect to any multi-player server address (valid or otherwise) typically resolves the problem.
Occasionally, some chunks of the map do not update with the day/night cycle, as seen here. Also, even in caves or closed environments the player can still see lighting bugs, (i.e An area has full light and it has a small spot of full darkness next to it. When the spot is edited, it changes to normal.) These glitches are quite common and can be annoying.
If you enter Fullscreen mode, then exit it, mouse clicks will no longer work for game dialogs (game menu, inventory etc.). However, mining and using items still work. Pressing Esc, waiting for the game to save and restarting the client resolves this problem. Here is a topic on Minecraft Forums related to this bug.
If you place four blocks so that they can stop the flow of water then place water or lava into it you can put a cactus piece into it.
If you hit a movement key and at the same time open inventory or click that movement key will become "stuck". Pressing and releasing the same movement key again will stop you again.
If you disconnect from a server while a message is displayed, and then load a single player world, the text will appear in SSP as shown here.
When Java crashes, your work sometimes cannot be saved and you may have a new respawn point.
Sneaking does not prevent you from falling off beds.
Particles (torches, furnaces, etc.) do not "adjust" to face you, some of them may look flat or even be invisible while sleeping.
If you sneak while sleeping, you can see your face or arms.
If placing a bed on an outside facing one block thick wall, Mobs can sometimes spawn on or near the bed with you sleeping in it. This causes you to wake up during the night in danger of being killed by a hostile mob.
If you try to activate a bed you are standing on it will not work giving the error message "You can only sleep at night".
If you try to activate a bed when you are too far away it will not work giving the error message "You can only sleep at night".
Beds placed in fully enclosed (on both sides and with only one space above) areas can cause you to wake up inside a wall, killing you and potentially destroying your items
When entering a boat on ground it will show a splash effect similar to that of water.
If you manage to stand on your boat while it is under water, the boat will be unable to move.
If you go under a water stream your boat will accelerate and rise upwards.
If you save and reload while in a boat, you will no longer be in the boat.
You can, although slowly, move in your boat on land.
Pressing F5 whilst in a boat will show your leg/foot armor protruding from the bottom of the boat, even though your character is sitting.
If you place a boat on the ground and drop sand onto it, the sand will repeat the falling animation on the top of the boat and you will be able to pass through it.
Exiting a boat will make the player to fall through it. (An answer is needed what causes this.)
Cactus also has a South/West rule for applying damage. Placing a block above a single cactus piece prevents you from stepping on the cactus and prevents you from taking damage by pushing against the south or west sides of the cactus. The north and east sides of the cactus can still hurt you.
If there is snow, fire, water, or lava on a block, then a cactus can be placed on top of that block violating the usual rules for placing cactus. When the cactus grows it will recognize that it is improperly planted and uproot itself leaving two loose cactus blocks.
A chest may always be placed on top of a block that has snow, fire, water, or lava on it allowing you to create triple (or larger) chests. Naturally the interface for these over-sized chests is buggy (As shown here).
If you place a door next to a Cactus it will clone the door giving you two doors (unlimited doors) shown Here.
If doors are placed next to two stapled cactus-blocks, the door will immediately get destroyed and will drop two doors instead of one. One door can not be collected. If a door is placed next to two stapled and newly planted(small) cacti, an uncollectable door will be dropped, and a door window frame will remain, which drops nothing.
'Double doors' do not open simultaneously as one might expect them to.
Fire has a South/West rule for applying damage. Placing a block directly above a fire prevents you from stepping into the fire and also makes it impossible to damage yourself by pressing against the block from the south or west sides. The north and east sides of the fire can still hurt you.
For some reason, it seems that it is possible to have "Invisible Fire", fire that is dark and unlit.
Related to forest fires, it seems that after burning sections of trees, there are these lit-up areas of light.
When destroying a Furnace, unlike Chests, anything inside the Furnace will be permanently destroyed.
If you access a furnace and press the jump key, sneak key or a movement key, your character will act as though that key is still being held even after exiting the furnace's interface. This can be fixed by pressing the same key after leaving the furnace's interface.
The fuel material inside the furnace will be invisible and the furnace still plays the smelting animation. Needs context
Furnace emits light even if it's face side is blocked.
Gravel or sand will not fall down if a torch is placed between the time a block underneath is destroyed and before the sand/gravel begins to fall. Example
Gravel or sand will accumulate into resources if a torch is place between the time a block underneath is destroyed and during the time the sand/gravel is falling to fill in the spot. Example
Gravel or sand will not fall down if snow is underneath it.
If you break a block below gravel or sand and are walking into gravel or sand, you will literally walk into the gravel or sand.
Collapsing two blocks of sand or gravel on you and staying off so you are still inside the sand/gravel blocks but you don't get harmed. You can see through blocks that are connected to the sand/gravel blocks. This is an easy way to find caverns.
If you place a sand or gravel block then quit the game before it starts falling, upon reload, it will float. If a nearby block updates, it will fall.
Inserting a record and removing it before or after the song ends will cause the jukebox to eject a duplicate. Only one of the records will be retrievable, but the second will remain stuck in the world and eventually disappear after a certain amount of time. It is possible to abuse this bug to spawn hundreds of unobtainable records.
Sometimes when you step in the lava, you won't be burned and you will get no damage.
When lava is touching the same corner as you it has a possibility of burning you. This will only happen when the lava is at the corner SOUTHWEST of you. (see South/West rule)
Example
N
=^=
W +== E
++=
S
= is a block + is lava ^ is you
Note: Items can burn when touching the corner.
Note: This can also happen with water, but water only collides with you.
Levers can be placed on the bottom of a block, as long as there is an open space, and a block horizontal to the open space. The lever will act as if placed on the horizontal block, but looks glitched, as shown here: Media:Brokenlever.png (Minecraft 1.3).
When spawning mine carts on a small track, they will gain momentum from colliding with each other.
It is possible to gain neverending speed for a mine cart from abusing the bug by spawning many carts on a small track.
Riding in a minecart on above track may cause your player's image to disappear until you die or reopen Minecraft.
Riding a minecart at the top of the map makes the player invisible until you leave the cart or ride downwards.
Sometimes moving minecarts disappear completely.
If you open your inventory while in a minecart, your player hand model will not function as expected.
Riding a minecart into a Nether portal causes you to become stuck.
Removing a minecart while riding in it will cause you to go through the ground, but only if the track is sitting on a non-solid-block and air is all around it. If there is an non-solid-block underneath the block the track is on, this will cause you to fall through.
If a minecart enters lava, the client will freeze. If the player is in the minecart when it enters lava, the client will crash.
If you make a cannon that can fire a lot of TNT and then place a single track facing away from the cannon on the "firing spot" (the place where you put the TNT missile), put a minecart on that track and detonate the TNT while in the minecart, you will fly up into the air (if you have god mode on) and when you come back, you will find more than one minecart item near the cannon. This has only been proved in version 1.2.2 and before.
Minecarts can go off tracks or crash through the ground if their momentum is too high.
Placing a minecart behind a wall of lava or water and right clicking the minecart behind the lava/water makes the player to enter the minecart without touching the lava/water. This trick can be used as a "teleport" or a secret entrance.
Minecarts that are not ridden will slow down if they are too far from the player.
As of Beta 1.3, Zombies and Spiders cannot do damage to the player unless the zombie/spider is above the player.
If a mob is riding a minecart and 2 or more mine carts get stuck in each other, after destroying or moving the carts away from the other carts the mobs will be invisible.
When up close to a Zombie Pigman, the inventory GUI will become much brighter.
If you are above a Ghast's height and are standing still, Ghasts will shoot fireballs over your head, without damaging you.
Ghasts will shoot at the camera in 3rd person view.
Squids can spawn in unintended locations, such as from cavern springs or even in The Nether (If water is hacked in)
Mobs can move briefly before map data is loaded when signing out and loading the world, usually resulting in the mobs getting stuck.
If a painting is placed and immediately removed, there is a chance that the picture frame will get duplicated.
If a block is removed from behind a painting, it will pop off the wall when a player touches it after a reload, even if it is a multi-block painting and there are other blocks still behind it.
Paintings have no player or object collision (Players, Mobs, and entities can pass through them, and non-solid blocks can share the same position a multi-pane painting is in)
Placing a boat in the portal and entering it will cause the game to skip the "safe area" finding algorithm. This means that you will appear in the Nether world exactly where you are meant to regardless of blocks in the way. Example video.
Being killed in the Nether will cause a portal to be generated near your relative location on Earth, as though you had teleported back from your "final resting place" normally.
Riding a minecart into a Nether portal causes you to become stuck.
Opening the inventory then crafting while in a portal will destroy the item you are crafting and make the loading screen text turn gray and double AND won't show the loading progress.
If the game is closed while entering The Nether, you will be sent to your spawn point on earth without held items.
If snow, fire, water, or lava are over a block than a sapling may be placed on that block allowing it to be planted in a non-dirt tile. After a short time the sapling will recognize that it is illegally planted and uproot itself.
If a block is covered in snow, fire, water, or lava, than sugar cane can be placed on that block violating the usual placement rules for sugar cane. When the sugar cane grows it will recognize that it is illegally planted and uproot itself leaving two loose sugar cane blocks.
Bugs in the terrain generation code can cause Sugar Cane to float
As of the Halloween Update (Alpha 1.2.0), snow will not fall, meaning that once it's destroyed, it will not come back.
The snow falling animation is absent, but if you have chunks from a world that was originally a snow world (pre-biomes) than snow will still accumulate on those tiles even though there is no longer any snow fall animation.
Utilizing snow, one can place saplings and cacti on any block. However, the cacti will break when they first grow, and the sapling will deroot itself after a while.
In snow biomes, water and lava lakes can generate below the snow and leave some of the snow floating.
When firing arrows at the opposite corner of the slab, your arrows may clip through and hit the block behind it.
Wooden slabs can currently only be properly collected with a pickaxe instead of an axe. This may be caused because of all 4 slabs using the same data values
It is possible for multiple water currents to crash against each other and create an inescapable rip-tide. Not only will this rip tide hold you in one place, it will also throw you from a boat if you are sailing it.
Under certain under circumstances, underwater players can breathe, and see through the water. An example is shownhere.
Like lava, when water is touching the same corner as you it has a possibility of colliding you.
Numerous strange objects will prevent the flow of water such as , signs, sugar cane, open doors, fences, half-blocks, etc.
If you access a workbench and press the jump key, sneak key or a movement key, your character will act as though that key is still being held even after exiting the workbench's interface. This can be fixed by pressing the same key after leaving the workbench's interface.
Glass placed in the same block as an entity will not cause the object to 'pop out'.
Mac OSX
On some Mac OS X Systems, the World Select screen will not appear at all, making the game unplayable on those Mac systems.
In other cases, the Mojang AB logo will appear green and the title screen and the game in dark areas will appear red.
In dark areas some sides of tile blocks will not render making a see through cave and grass and trees in daylight will appear purple, anything in darkness will also not render properly. The sound and music will also be weird. This has only been proved with non-Intel chip Mac.
Survival Multiplayer (SMP)
General
When entering a server, the player may fall into an endless void and eventually disconnect. This is caused by a large amount of server lag and there is no effective workaround.
If a player has respawned, he can place blocks on the block he is currently standing on. This will not decrease the block count in his inventory, effectively cloning blocks. This bug only occurs with non-opped players.
Full server world saves do not reliably save the entire world. This can be proven on a single person private server with whitelisting enabled when attempting to do a full server save via:
Disabling incremental level saving with 'save-off' on on Minecraft console.
Forcing a full save to disk with 'save-all' on on Minecraft console.
Archiving and saving the archived world with 'tar -xvzf save.tg world' on shell in secondary system console.
Turning back on incremental level saving by doing a 'save-on' on Minecraft console.
Enormous, cuboid areas (usually one or two chunks) of unfinished map open in random places. Caves, minerals, water, magma and mobs are visible when a Player peers into one of these voids. These areas cannot be walked on, causing a "[user] moved wrongly!" message to appear in the Server; however, players can ride minecarts through them with relative ease. If the void appears in the middle of water, Players can "float" over the void using a boat. Placing a torch next to one of these "void holes" or disconnecting and reconnecting to the server will make the land inside of them reappear. These have become significantly less common since the 1.3 update.
When you sneak (in third person), your character's feet are "in" the ground.
Seemingly as of Beta 1.3, some people get huge delays between the client and server, sometimes as large as 3 minutes. This is not like normal lag.
Arrows shot onto a wall cause the arrow to create a flickering wobbling repeat of the arrows movement. This happens mainly on glass.
Fired arrows will appear to come out backwards at first, then continue on a regular trajectory.
After firing an arrow, any other player will see a repeating rapid arrow fire at the state the arrow was fired. However, the arrows will not collide or damage anything. They will disappear upon reconnecting. Dispensers won't do this, though.
If you ride a boat over a chunk of water which did not load properly ( ex. the water is really there, but you can't see it and can see through the whole world ), the boat disappears.
Boat controls are having delay when you control them, because of lag.
When a Boat gets damaged (by a player), it does not shake.
Destroying a chest will spill its contents and every item in the chest will be duplicated. Only half of the items visible to the player can be picked up, so no items are gained nor lost in the process.
The disappearing seems to be caused by the same bug just in the opposite way. Instead of the server lagging behind the client and telling it that the item is still there the server will erroneously delete.
When attempting to stack doors, one will be deleted.
If you open and close a wooden door repetitively while jumping, you can catch yourself in the door and jump again. This can be used to reach 1 block higher places or to get on top of wooden doors overall.
The records duplicate if you eject the record before the song has finished. Only one record can be picked up however, the rest are client-side duplicates.
Engines consume coal but do not move under their own power, making them useless.
Minecarts that pass over pressure plates will sometimes not activate a redstone current, even though a "click" noise is heard.
A player will pass through the minecart, but when the player is passing through it counts as "pushing" the minecart.
Empty/Storage Minecarts start to behave strangely when they are too far away from the Player. They disappear completely, disappear until Players disconnect and reconnect, or suddenly stop on tracks despite having sufficient momentum.
Minecarts load before terrain sometimes causing them to be invisible until they are interacted with. Large transit systems and door water boosters are examples of when the issue occurs. (log out/in to reproduce).
Shooting animations (Ghast fireballs/opening mouth and eyes, Skeleton arrows) are not always visible.
Ghasts' fireballs occasionally do not explode, only lighting a small area on fire.
Sometimes mobs freeze in animation and can not be hit. They disappear after about 2 minutes.
Some users are reporting mobs will be invisible, but can still attack you. On update 11/24/2010 SMP health update post Notch explained that to see invisible mobs, players must set their difficulty to the server side difficulty or higher.
Upon death, all monsters around you will be frozen when you come back. you cannot kill them, or attack them, and they cannot attack you. You can however push them, touch them, and they will still make noises. Skeletons, and Zombies will catch fire, and it will flicker and not cause damage.
During severe lag, you can be killed by mobs or players without ever seeing them.
Hitting a mob a few times in a row before the mob receives the damage will cause the mob to receive the damage from only one hit, but the force of all of them, making them fly up and backwards a considerable distance.
Every mob will freeze, when the server is timed out.
A dead mob has it's corpse staying on the ground and shaking.
When slimes divide in SMP they often create many fake duplicates which are invulnerable, and inflict no damage. Disconnecting/Reconnecting causes these fake slimes to disappear. This bug does not occur in Survival (SP) mode. (Minecraft 1.3)
When slimes divide, they can create larger slimes.
Zombies, skeletons and creepers cannot be hit below.
If a monster spawner is exposed to sunlight, the sprite shown inside the spawner block becomes a pig, and the spawner will spawn pigs on any nearby grass block. These pigs are glitched client-side pigs and cannot be interacted with.
Additionally, if torches are placed around the spawner, it will cease to spawn pigs.
Pumpkins used as a helmet now display the carved face on the back instead of the front. Users wearing pumpkin helmets will still be able to see through the cut-outs but will appear in server to have a smooth pumpkin face and a Jack'o'Lantern grimace on the back of their head
Redstone Repeter
The particle colors for Delay/repeater blocks are the same of pumpkins. (Minecraft 1.3)
TNT lit by one user cannot be seen by another, though its effects can.
Occasionally, a TNT block meant to drop will enter a repeating fall animation (but not actually fall) when lit. When the TNT finally explodes, it will explode at the position it was placed.
Occasionally, a TNT block can also explode twice, but this will not damage the environment twice.
If a lot of TNT is lit, some TNT may explode but leave behind an image of an exploding TNT block that is almost completely white, and will hover in mid-air. The ghost TNT will not disappear unless the player disconnects and reconnects.
Using bone meal to quick-grow trees will sometimes cause "floating" trees to grow with sapling still at the base. Removing the sapling or using more bone meal can cause the tree to grow into an enormous bundle of leaves with no log base. These leaves will now respawn immediately after being harvested. The only way to remove these glitched leaf blocks is to burn each block individually (fire will not spread for some reason) OR build an umbrella above it, the shadow seems to instantly vanquish the leaves. - This glitch is vastly more common when quick-growing trees under another trees foliage. Again, disconnecting and reconnecting will reset these "ghost trees."
Planting a sapling and waiting a bit will sometimes yield tree trunks with weird distributions of leaves, and in some cases, no leaves at all. Trees can also grow but be invisible, making it impossible to traverse a tree farm after a while. Rejoining the server appears to make invisible trees visible again and fire will swiftly cause phantom foliage to be made manifest. You can also place a torch to make the phantom foliage appear.
Leaves from trees will overwrite some blocks, such as a nearby fence.
Placing a torch on Leaves does not make the 'pop' sound for the item being placed.
You may find yourself drowning despite having a full breath meter. This is caused by the client thinking that the player has gotten air, but the server thinks that the player is still underwater. This causes the non-synced breath meter
