Minecraft Wiki:Issues/Beta 1.9pre5

The fifth pre-release for Beta 1.9 has been recently released by Jeb.

''' Use the Discussion page first before adding any bugs onto this page. ''' Bugs can be confirmed by checking into the discussion page and make sure other people reply to your report and have the same problem.

= Bugs =

Bug Labels:


 * x = Minor bugs.
 * ! = Major bugs.
 * !! = Bugs that can crash Minecraft or a server.
 * ? = Possible bugs/features that you and the community (on the discussion page) are unsure about.
 * a = Annoyances.


 * u = Bugs that Jeb tested but was unable to reproduce.
 * f = Bugs that have been fixed in the next update.
 * s = Bugs that will be skipped/ignored for now.

Blocks

 * ! Placing pressure plates (wood or stone) behind a door that is oriented to south or north makes it work vice versa (door closed when you stand on it, open if not)
 * f Wooden stairs drop a wooden plank instead of the stairs.
 * s Dirt blocks that are irrigated shimmer blue on the side when viewed from underwater. Also the water-side of submerged glass blocks.
 * x Glass blocks do not displace loose blocks underwater. What does this mean? /jeb
 * When placing a glass block on a dropped item or item stack it encases the item (the item occupied the same space as the block) instead of being moved to the side. Leaves exhibit the same behavior.
 * us Tall grass can be generated on dirt and gravel in NPC villages.
 * u Spruce or Pine, when converted into sticks, sometimes cannot be made into tools. This bug is absent with Oak and Birch.
 * f When a water block is placed with empty space underneath, a column of source block is created under the water block. (Maybe an intended feature? Might help keep oceans from having random holes where land used to be.)
 * ! Quitting to title menu while standing on a pressure plate will activate it forever. It must be rebuilt in order to make it usable again, this goes for items on wooden pressure plates too. [Verified]
 * s Flowers can spawn upon sand blocks but cannot be placed upon sand blocks by the player.(Only seen with yellow flowers)
 * ? Patches of swamp water can be seen in the middle of a lake with no swamp land around it.
 * f Arrows do not get stuck in lilly-pads. Lily pads are walk-able now /jeb
 * s Snow Golems still attack mobs in creative mode in which are neutral.
 * x Creative mode inventory missing items :
 * 18:1 Spruce Tree's Leaves
 * 18:2 Birch Tree's Leaves
 * 18:3 Spruce Tree's Colored Leaves
 * 31:0 Dead Bush placeable on dirt and grass
 * f 31:1 Tall grass
 * f 31:2 Fern
 * 44:6 Alternate Stone Slab
 * 52:* (Working) Mobs Spawners
 * 60 Farmland
 * 78 Snow Plate
 * 90 Portal
 * 97:0 Silverfish Stone
 * 97:1 Silverfish Cobblestone
 * 97:2 Silverfish Stone Brick
 * 99 Huge Red Mushroom
 * 100 Huge Brown Mushroom
 * f 111 Lily Pad
 * 119 End Portal
 * 120 End Portal Frame
 * 263:1 Charcoal
 * 2267 Music Disc (C418 - where are we now)
 * x Creative mode inventory unneeded items :
 * 83 Sugar Cane Block - There's the "Sugar Canes" item (338) for that
 * 92 Cake Block - There's the "Cake" item (354) for that
 * f Enchantment Tables break with a single punch and are destroyed permanently, although they can be mined with a pickaxe.
 * s It is possible for a lilly-pad to spawn underground and on flowing water. Example:
 * ? Chests connect with each other when placed three in a row, with a graphical overlap. When opened, they show the inventory of 2 like normal. How do you place three next to each other? /jeb -i believe this also happens with iron bars if it didnt get fixed with the panes
 * f Eyes of Ender will sometimes go to areas without an End Portal. An example seed for 1.9pre4 which suffers from this bug: 1883114686416083372. No seed which reproduces the bug has been found for 1.9pre5. This seed will reproduce the bug on 1.9pre5: -7521364253261532640
 * x Dead bushes don't get placed in creative mode. I don't understand what this means /jeb
 * x Lily pads can now be placed by right clicking on the side of a block 1 space above water, though when placed on vines using this method, the vines disappear. Same happens with mushrooms, though they are just broken. May also work with other blocks, haven't tested this yet Thanks for the info, but what is the bug? =)
 * f When placing a halfblock of sandstone, and another one under it, then another one over all of them, the blocks combine into 1 sandstone block at the bottom. -this happens with every type of slab, has it been fixed for all of them?
 * ! Pistons can be used to generate an infinite supply of sand and gravel blocks. Example:
 * xu Cant place a torch under a stair block
 * [X] Cant place a torch back of stair block
 * fs Glass pane don't connect to slabs, stairs and (wooden?) doors: Fixed the problem with double-slabs, but otherwise they attach as intended /jeb
 * x Pistons can be powered by blocks that are not directly connected to them (diagonally above or 2 blocks above) leading to changes in those blocks not updating the piston, but when the piston is updated it will take those blocks into account.
 * f Save and Quit while water and/or lava is flowing downwards from a high source block can lead to weird freezes in state upon reloading the world (suspended blocks of fluid).
 * a Slimes in SMP are very buggy while in caves. They are very hard to kill. They keep jumping extremely high and falling from the ceiling
 * f Placing a redstone repeater to the side of a jukebox causes a lighting bug on the repeater.
 * ! Minecarts with furnaces can't push minecarts on east/west tracks. This is really annoying after you just dug a 3x3x1k east/west tunnel. Powered minecarts DO work on north/south tracks.
 * xu Some signs won't move from a chest to a inventory with shift+click.
 * x Wooden half blocks are destroyed faster with a pickaxe instead of an axe.
 * A If a nether portal is placed by the user, it disappears when any adjacent block is changed. This includes placing a second portal block, in which case they will both disappear (After doing a rotation snap if necessary). The portal blocks are obtained using the /give command on SMP. Portal blocks need to be next to a obsidian block in order not to disappear. Otherwise it'll realize that it can't exist there and disappear.
 * x Very rare, but I have had tall grass generate on water rather than grass. (I don't have a copy of a seed for this, though)
 * x The side grass texture still uses the old dirt texture.
 * f Fence Gates have their collision boxes as the entire cube.
 * x Fences attach to Chests.
 * x Placing blocks on glass and iron bars result in many illegal decorations - tinyurl.com/3s44hx7

Crashing
This can commonly be fixed by using the below line in a file ending in .bat or .batch. This works with 64-bit OS machines: "%ProgramFiles(x86)%\Java\jre6\bin\java.exe" -Xmx256m -Xms128m -cp Minecraft.exe net.minecraft.LauncherFrame And this works for 32-bit OS machines: java -Xmx256m -Xms128m -cp Minecraft.exe net.minecraft.LauncherFrame
 * ? Some users report F11 causing a blackscreen crash. I have experienced this before usually fixed with pressing F11 fullscreen glitch possibly happens when in game full screen when to tab out users press F11 this can be avoided by alt + tab to tab out like that - alizter1234
 * !! Maximizing the window and moving it to another monitor before pressing 'E' or right clicking an interface after starting the game will result in the game crashing with the "Saving Chunks" screen upon pressing 'E' or right clicking any interface in Mac OS X.
 * !! After playing for a few hours an error will occur causing the "Saving Chunks/Out of Memory" error. This often happens while running 32-bit Java on a 64-bit OS. But since 1.9-pre5, it doesn't happen that often anymore.
 * !! Game (clients and ?servers?) cannot tell when it is in distress / running out of memory / processing due to an entity (Mobs or blocks on the ground) overload. Propose that when memory/processing usage is approaching critical levels, the game should take much more aggressive management of entity removal.  This can be achieved in vanilla ssp/?smp? through standing next to a mob spawner dropping mobs into a trap outside the check range but mobs remain inside the "mob reborn" range (this may have been a bug of the above memory leak, the game crashed and I was not able to restart it).  This can be achieved artificially with MCEdit with a 2x2 chunk room 10-20 blocks high and replacing the air with torches or similar.  Entity overload on SMP creative through the use of scripts mass-dropping blocks (before the ability compress blocks into a single unit) is/was a well known and often abused griefing tactic.
 * !! Placing a chest beside a Brewing stand in 1.9pre5 multiplayer will cause it to look like it is not there (transparent), right-clicking on it causes the game to crash. You can still break it without Minecraft crashing. After logging back on the chest will work properly.
 * !! Hitting Alt + F11 causes a crash and a error report to download to your desktop.
 * !! Placing a chest, then removing it, and then placing a sign or enhancement table on that place will crash the client. Tested on Creative SMP'

Files

 * f On servers if the ops.txt file is missing the message generated states "Failed to load ip ban list" obviously copied from banned-ips.txt message and not modified.
 * s Saved worlds show up as 0.0 MB. Updating at startup is too slow, and fixing it ingame is too much work... I'm hiding the field instead. /lazy-jeb
 * f After loading a world and quitting to the main menu, some region files remain being opened and locked by the region cache manager. Altering these region files requires the game to be fully shut down first, which makes external edits cumbersome.
 * ! Sometimes after dying on a hardcore world Minecraft fails to delete files and after starting a new world with same name you may find old chunks.

Gameplay

 * ! If you switch between Survival Mode and Creative Mode on the same Map - switching back to Survival Mode does not work properly. (you will be still able to fly around)
 * x In single-player, leaving an area causes the game to "spike" for a moment, but not when re-entering it. This may be exclusive to the area the user's bed is in.
 * s pressing the "a" key to strafe left will cause all chunks to reload. entities are not affected. unsure if there are any negative effects of this, other than lag, annoyance, and the ability to find nearby dungeons (in the same manner as the old " f render change" glitch). possible causes include hitting an Enderman, having an Enderman look at you, hitting an Enderman while something else hits you, critical hitting an Enderman, or falling while watching an Enderman watch you watch it watch you. Sounds like your F3 key is stuck... F3+A does the same thing as F3+F, except it doesn't change the render distance /jeb
 * s using a hack to change mode to creative then back to survival you will still be able to fly and have infinite health. I don't care about hacks, stop wasting my time /jeb
 * s There is no apparent way to turn off f10 causing the game to be unplayable without a reinstall. It also seems to be on no matter what save I go into. What does F10 do to you? On Win32 it selects the system menu (same as Alt in most cases) /jeb
 * x In SMP, the server won't load the End or Nether; therefore making both worlds not generate (the End is just the 5x5 obsidian platform you spawn on).
 * You must dig up from the obsidian you spawn on, you only have to go up 5 blocks. True. i needed to do it also
 * a Unable to put armour on using creative.
 * x When entering The End, it is possible that you will spawn off the generated blocks and be placed on a 5x5 block of obsidian. If played on a mode other than creative, it would be difficult to make a path to the rest of the map. (gravel/sand?)
 * x Redstone does not detect when redstone powered items are adjacent and direct power to them while it does detect repeaters.
 * x Noteblocks can only be powered in 3 ways, 2 of which is bugged: Direct wire, Torch underneath, and a direct repeater.
 * Firstly, Destroying the torch under the noteblock does not turn off the noteblock. Lastly, The repeater functions backwards, it causes the noteblock to play when unpowered (Sending power does not make a sound, but removing it does)
 * x If you exit the game (or or the game crashes) while in a minecart you will start next time buried up to the waist in the ground. If there's lava one block down you'll burn. If you exited the game in a crash often the minecart is duplicated.
 * x If you exit the game (or or the game crashes) while in a boat you will start next time on the sea bed with the boat zooming away from you.
 * ? While using a bed you will always be interrupted by a hostile mob. (even when the bed is well within a mushroom biome where no hostile can spawn) It seems the buffer distance between you and mobs has been increased to 3? - Are you in a house with double doors? Double doors allow mobs to wake you up unless it is redstone locked.
 * ? Sugar Cane seems to grow at a reduced rate.
 * ? Endermen will attack you in Creative mode if they bump into a wall and you are near them.
 * ? When logging on with a random username and password you can play Minecraft Singleplayer for free. (offline) -- True, but you must have offline (.minecraft) files, then you can log in with a random username. While an offline server would work with this method, an online server doesn't.
 * f Efficiency enchanted picks (tested with Efficiency 4 diamond pick) have little effect on reducing Obsidian mine time. Not sure if intended. Eff. IV should take 40% of mining time - 0.6 x 15s = 9s to mine obsidian.  Not tested.
 * x Water on top of fence posts can cause entities to hop in place if they move in any direction against a wall 1 block or more higher. This does not happen at all at the .5 minimal height for collision next to water on a fence post.
 * ? When you're in a snow Biome in Beta 1.9 pre5, if you make a fountain of Water and wait for it to freeze, you can take it with a Bucket, and the the next flowing water will turn into Ice.
 * ? Mushroom Soup does not stack. It's intentional.
 * x Being suffocated by blocks (i.e. dig down 3 blocks and place 2 sand blocks above you) while in 3rd person will cause the camera to revert back to 1st person.
 * x The client can place and break blocks 1 block further than the server thinks it can; blocks destroyed this way may reappear. This can be an annoyance for players. The extended reach is usable horizontally but not vertically.
 * a Birch and pine leaves don't appear in the creative mode selection screen.
 * x On the world creation screen, when you resize the window, any name you entered in the editbox will be reset to the default "New World".
 * a In creative mode boats are not infinite forcing you to refill your item bar after placing one. Same with TNT
 * ! When going into The End, the player turns invisible and the FOV turns all the way up and cannot be turned down. After a little while the screen turns upside down and the FOV becomes increased again.  Yet, the FOV slider on the menu is still at 0, but the game is beyond the maximum setting.  This bug then carries over to all other saves (worlds). Hold N and M and then Y and H (M/N = Roll, Y/H = Zoom)
 * x Sugar and Eye of Ender are rendered incorrectly as a tool in 3rd person mode.
 * x When playing on multiplayer, a slight lag causes thrown eggs to disappear. Sometimes a phantom egg is placed back in the inventory, also.
 * x Sometimes when standing near a repeater you will fall through one level of blocks. (And will sink into the floor up to your waist). Seems to happen more when the ceiling is only 2 blocks high.
 * ! Strongholds can be generated without an End Portal. (Sample seed: -7521364253261532640)
 * x You can't hold down the left mouse button to continuously attack any more.
 * x You can't hold down the left mouse button to to break a minecart any more.
 * a The game has a very slow level income the higher the levels go for enchantments. e.g. You need to kill about 2-4 mobs to gain level 2 when you are level 1, but like 20-40 (guessed) mobs when you are level 20 and want to reach level 21. Since high level enchantments often still result in weak enchantments it's not worth saving levels for them: For example after spending hours and hours of time to get to level 20 killing hundreds of mobs it's kind of frustrating to just get an "Efficincy II" enchantment which will make you save a few seconds mining time in total.
 * This is not a bug, but it is a balance issue. Suggestions get gathered at the discussion page
 * a A lot of clicks are necessary to find an specific enchantment level in the enchantment table once there are a lot of books around it.
 * It is notable, this annoyance is the same basic issue with painting's random placement
 * Would be better if the enchantment levels are binomial distributed around the players level, but still capped by the amount of bookshelfs
 * x Entities can gather up damage from lava in the nether to have it all expelled onto them upon touching dry land (even those entities who are immune to lava damage can amount insane amounts of damage just by taking a lava bath for a few seconds).
 * x Similar to the entry above. Minecarts can accumulate damage via high falls.  This damage is expelled onto the entity if the minecart touches a block that doesn't have a track on it (IE cart falls through a 24+ block drop before reaching the player; player hops in and takes a ride; ride leads to a deadend rail and cart skids off the last track; player dies).
 * ! Sometimes player will sink through floor; after death problem still occurs.
 * Still many blocks are not on the efficency lists of tools and therefore take ages to mine regardless of the tool . Especially annoying is that better tools/ enchantments do not work on these. In the following list the tool it should mine faster is in the brackets behind: fences( axe), fence gate ( axe), nether fences ( Pickaxe), nether bricks ( pickaxe), bricks         ( pickaxe), workbenches ( axe), stone bricks ( pickaxe), cracked stone bricks( pickaxe), mossy stone bricks( pickaxe), iron bars( pickaxe), iron doors( pickaxe),wooden doors ( axe), myscellium ( shovel),furnace ( pickaxe), disperser ( pickaxe), redstone ore ( pickaxe) ( at least a little speed improvement with an diamond pickaxe vs iron one would be nice)
 * x Exploring previously-unexplored deserts in SMP causes the player to run into invisible cacti, which cause damage and stuttering movement. Disconnecting and reconnecting or leaving the area and returning makes them visible.

Graphical

 * x While sat in a minecart wearing armor,opening your inventory shows you sat on your boots as well as wearing them.
 * sx Activate F3 and open Creative Inventory. If you scroll down the background of the CPU-Time-Usage-Table (right bottom) disappears. Seems to happen if you see the "Golden Apple" with its graphical effects in the Inventory. //Update: This happens with every animated item in your inventory. Probably just some GL setting that isn't cleared, but I won't spend time looking for it right now. /jeb
 * x While in front first-person the fire on the players body while burning is not visible to the player.
 * x Swamps have a horrible transition from any biome to a swamp biome leaving some nasty looking colors. Example:
 * x Chest armor doesn't move when swinging arms if looking in certain directions.
 * x Due to the new camera positioning keys, switching keys (such as I for inventory, instead of E) causes "unintended" camera panning from the player.
 * x If you eat rotten flesh and get infected then switch to third person and facing the character the infected animation doesn't play. Tested with fancy graphics and the default texture pack.
 * ! Swimming/sailing in the ocean causes the horizon to flicker obnoxiously (since 1.8). It occurred in the 1.8 update because the water level was lowered one block. Previously, water level was at 65, now it's at 64. When you used to dive into water at level 65, the horizon would turn blue to create that underwater effect. But now when you dive at the new water level, the horizon still behaves as if the water level is still 65, causing that horizon glitch.
 * x The wheel texture is flipped upside down on one side of Minecarts.
 * x When you die, the player model in the inventory screen also appears dead, blocking some parts of the inventory screen/slots.
 * x While you're in bed, the experience level number doesn't fade out.
 * x When underwater with the camera position changed, it resizes the blue square filter you get when being underwater.
 * x After pressing f6, if you hit left shift to crouch, it inverts your movement controls.
 * x Water and lava drips under blocks where it probably shouldn't such as glass, signs and ladders
 * f Looking directly at an entity while holding a map will cause the map to become white (see http://imgur.com/5F0Wq).
 * f If you press F3 and exit the world you are playing on, the F3 data/screen will still be visible when you are in the Minecraft menu but you cannot turn it off
 * s Part of the player's skin, specifically the bottom of the head and hat, is facing the opposite direction. Tested in both SSP, SMP, and all the gamemodes. Sorry, but the new alignment is staying. If it's important you need to update your skin. /jeb
 * x If tree is in the middle of two biomes, it may cause an overlap of of leave blocks at that area.
 * x This is kind of major cause it allows you to look through walls. So what you do is play around with Y,H,N and M, (aka camera angles/depth/etc) then reset it(hold Y and H, and N and M) and press F5. If you are lucky the camera will be screw up and if you look down you will see under ground all the caves. You can't see your character tho cause its like facing the opposite way.
 * x Bucket will not pick up water or lava but still effects the flow. Possibly the effects of switching from creative to survival with an out-dated hack.
 * x After using mode switch hack?: Compasses point towards the original spawn point instead of payers bed despite setting it as respawn/sleeping in it. It's supposed to do that... Check here
 * x Linked to the Audio Rain glitch, in chunks where the rain sound will not play, you can also see that, while the rain is falling, it does not splash against blocks on that chunk.
 * x The 3D Character's Movement in the Inventory screen causes some laptops and older graphics cards to crash (It never happened to me before 1.9.5)

Lighting

 * f Redstone Repeaters placed between two full blocks are dark when placed along Z axis. They are properly lit when placed along X axis.
 * x Black and white flickering on all mobs and the player arm when playing Minecraft on Windows XP. Has occurred since 1.8 // cannot reproduce.//reproducable, maybe only with Intel graphics chips?
 * x Black an white flickering on chests and all placeable objects on Minecraft Windows 7. Occurred since 1.8 // cannot reproduce.//reproducable, same with WinXP//same as above (?)
 * ! This lighting bug is better explained by a short, voiceless video here [Skip to 1:20 for the bug; earlier shows how to create].
 * x Sometimes overhangs create pitch black shadows, as shown here File:2011-10-27 16.52.37 copy.png. However, when one gets closer to the cliff, the lighting is updated and the pitch black shadow disappears (as shown here File:2011-10-27 16.52.51.png).
 * x If the block adjacent to a water source has a lighting issue, the bubble particles will become black.
 * f Glowstone behind glass is odd, the light shines through but the glowstone itself is almost black. Example:
 * u Chests and signs are often black or very dark even when in a well lit location I can't reproduce this in pre-5, can you show me exactly how you build to make the chest dark? /jeb I think this only happens when using an Intel graphics chip.
 * u Enchanting Tables Books are often black or very dark at some angles What angles? APPLY SCIENCE! =) /jeb Same as above
 * x Light source is placed underwater and destroyed the light stays. - Fixed in the newest Pre-release.
 * x Arrows shot at the bottom of a block appear dark, even in well lit areas.
 * x Signs flicker dark. //maybe only with Intel graphics chips?
 * x Glowing redstone ore appears darker if light level is high Redstone block lighting.
 * x You can see chunk boundaries 'under' ice on some systems.
 * x Occasionally some leaf blocks on trees that become enclosed later will continue to generate somewhat dim sunlight (light level changes based on night/day cycle). Forcing a lighting update doesn't fix, only destroying the block will. Examples:
 * ! On many Mac OSX systems there is harsh visual lag, and you can see through blocks partially (not due to textures) as well as at night the lighting inside is blue as well as odd strips going through blocks
 * ! not only that but there are bugs letting you see through blocks when it is dark even in smp
 * x light "leaks" through the corners of stair blocks Example Image

Maps

 * ! When you are flying on ice, you will see the sides of the chunks (Confirmed for versions 1.6, 1.7.3, 1.8.1, and 1.9pre5)


 * ! Created a map prior to 1.9pre5. After getting 1.9pre5, every new map made is an exact duplicate of the first one regardless of where it's made. Check and make sure you're not holding down shift when crafting the Map; this will always create a duplicate of "map_0"


 * f Using a map, while in a boat, at night, causes the map to become "highlighted" when the player looks down at the map.


 * u Map arrow don't match real looking direction.


 * a Blocks which use damage values to select their appearance only show the default color on a map, e.g. an area full of red wool will show up as white on the map.


 * u All maps made will center on the location where the first nap was created

Mobs
''Correction: you can see Endermen and spiders far away in fog.
 * f The cow, pig, wolf, sheep and sheep fur rear texture are upside down. It's maybe a general bug and maybe concerns all mobs/items/entities like boat, cart, chest and sign... It does affect the underside of player's head (1.8.1 was fine, during pre5 I noticed the bottom of my chin was now at the back of my neck; not sure when it started). Fixed by updating the skins /jeb
 * f Spiders, Endermen and silverfish will still try to attack you even if you have not provoked them in creative mode (other hostile mobs do not ).
 * x You can see see mobs far away in fog, though they are white.
 * u In a dark area, creepers and skeletons don't attack you. Creative mode? /jeb
 * a All (non aquatic) passive mobs make a bee-line for the sea. After a short while the land will clear of livestock which can be found floating offshore or trapped in ponds and pits. Includes cows, pigs, sheep & mooshroom cows. Chickens seem less affected.
 * This may be due to mob pathfinding directing them to attempt to reach a point below them. I have witnessed chickens climb a dirt spiral to jump and float out of a pit, so this may be a case of the pathfinding algorithm trying too hard to move in a direction.--PlNG 20:28, 29 October 2011 (UTC)
 * a Passive mobs constantly bounce when next to fences even though they cannot get over.
 * ! Mooshroom spawn too much in some area (see http://tof.canardpc.com/view/993ab614-4193-4b24-9d04-fcadd5c3f517.jpg). More than 29000 was removed with the help of MCEdit. The Mooshrooms spawned back after several minutes.
 * f Sheering baby Mooshrooms yields a full grown adult cow rather than a baby cow. Possible exploit to gather beef faster from breeding by bi-passing the time spent to age.
 * f Slimes and Magma Cubes are voiding several spawning algorithm rules. Such things as spawning on top of blocks labeled in the game as non-spawnable (glass, half steps, stairs, etc); spawning inside of translucent blocks next to air blocks, such as spawning inside of a piston block; spawning inside 1x1 block spaces that contain translucent blocks such as redstone, repeaters or torches.
 * After more research and testing, I have found this is caused by them ignoring the collision mask for translucent blocks. I've witnessed all sorts of weird stuff like them spawning inside of extended sticky pistons holding solid blocks and unable to move because of the pushers collision mask; spawning inside of glass with a solid block below it; spawning inside of extremely tight spots because the head layer was glass or piston and spawning on top of things like repeaters, half steps and the like when they clearly have a collision mask.  I could not replicate this with any other mobs, so the mistake lies somewhere in the code for cubed entities.
 * ? Ghast hit box (and collision check when spawning) are set approximately one block too low.
 * f Slimes and Magma Cubes do not despawn when setting to peaceful despite being hostile mobs at all sizes. This is indeed a "feature" but it was also not as intended when originally coded.  The original intent was to allow the smallest version of them to spawn but remove the rest since the smallest ones do no damage, just annoy.  This clearly is not how they have been behaving all these months.
 * u Chicken clips through gravel block and asphyxiate while following the player with wheat. How? I'm unable to reproduce this /jeb The easiest way I've found to reproduce this is to spawn a massive number of chickens with eggs in a confined space, and eventually the chickens will kill themselves through suffocation. not exclusive to gravel, though.
 * f Endermen may teleport after the player deals a killing blow resulting in their drops appearing elsewhere, often out of sight of the player and therefore lost.
 * x Mob path-finding is extremely lackluster and can easily break in tight spaces. In fact, it is so faulty that even a single block placed well over 50 blocks has a chance to cause mobs in a tight space to behave completely wrong; typically resulting in mobs blatantly ignoring the player entirely.
 * x Mass amounts of Spiders may collapse into a super dense spider ball, unable to escape the hitboxes of other spiders even when there's room, requiring that they be pulled apart one at a time. Spider Ball
 * f When trying to feed pigs with saddles wheat, it does nothing, and instead just mounts them.
 * x No more wool produced by sheep after a single shave. Tester this bug on multiple machines on SMP and SP.
 * x Chickens disappear once they mature into adults.

Multiplayer Related

 * ! Reducing server.properties view-distance drastically reduces/eliminates mob spawning in SMP
 * ! No Ender Map other than Spawn platform. (After extensive testing... Might have just spawned Far off the island.....) -Flamespinner
 * ? End Portal spawns you 1500 coords away or so from the floating island in the end. -Similar to above, you have spawned far off from the island. Ive had this happen to me too and was also 1500 blocks away (cant remember if it was X or Z axis, though).
 * x When exiting a minecart after riding it, the player floats and can clip into blocks. This condition only disappears when restarting the Minecraft client. This also happens in some cases where water is flowing down on top of you and you place a block above yourself. Restarting client (rather than reloading world) confirmed to resolve this.
 * x When an arrow is shot at a block, the shot arrow floats to the top of the block. It does not stay at the position it was shot at.
 * ! Nether Portals : Same bug as portal to The End (Portal is created above a huge lava lake, land is far away)
 * a Servers could use join/quit DDOS/flood protection through queuing, or at least the ability to limit/combine/reduce player announcements.
 * ! Client-side world holes are still a frequent occurrence in multiplayer games.
 * [U] From pre4 thread: "Blocks are not always what they seem to be. For example, a Dirt block can look like a Stone block.". It seems that the cause is that the client got one chunk with wrong data since it can be fixed by rejoining the server. The bug is very rare and very old (at least an half year). For video evidence of this, or a bug related to this, see www.youtube.com/watch?v=mlPkKtCaXyw#t=1340s at time index 23:10.  This video is from Beta 1.2_01 and doesn't depict the exact manifestation of how this bug appears now.  The video linked shows a diamond block appearing as stone.  Once broken, it is reformed as a diamond block, which could then be broken into a diamond item.  This is slightly different than how it manifests now, which is, that the diamond block would appear as stone, only to break into a diamond item without the intermediate diamond block being reformed.
 * x Use of multiple TNT on SMP occasionally leaves 'ghost' TNT tiles (old bug, been around since as far back as 1.2.3_04 as per YouTube video). This is a client end issue, as re-logging will typically remove any ghost tiles.
 * x Similar to TNT issue, when clearing high pillars of sand/gravel from the base up, some times you will encounter this problem, too.
 * ! Enchantment : The enchantment animation can not be seen by other players (tested on multiple machines).
 * xa Slime mobs, maybe magma slime either, move in very annoying way, the bounce rapidly up and down, and tend do clip over a ceiling/floor. this happens mostly with the tiny slimes,sometimes with medium, never noticed with big slimes. When they appear to clip over the ceiling, their collision frame is on the upper floor AND lower floor simultaneously, however, they attack can occur only on the floor they actually are. This makes them very difficult to kill, because player never knows, where they really are. This bug occurred in earlier versions (1.7, maybe earlier), but since slimes start to occur on upper map levels, it made them really annoying.
 * ! Players with slow internet connection can only hit mobs with melee attacks on the head. This is not exclusive to 1.9, as it goes back at least to 1.7.3.
 * a Whitelist toggling in the console doesn't appear to do anything. whitelisting seems to work, but requires a restart to activate/deactivate
 * xa Mob Spawners in SMP all appear as pigs.
 * xA Not a bug per se, but there is no flag in server.properties to allow/disallow travel to The End in SMP. (like the "allow-nether" flag)

Memory/CPU General

 * x The Macintosh version uses 32-bit Java, even on 64-bit computers (This is because the launcher specifies 32-bit java, but there is a fix that requires Xcode and very precise changes to the application package.) For a simple alternative to launch Minecraft in 64-bit Java, use this terminal command:
 * java -Xms512M -Xmx1024M -jar /Applications/Minecraft.app/Contents/Resources/Java/MinecraftLauncher.jar
 * Same here, on Windows 7 64bit, unless you use a batch file, or shortcut:
 * "C:\Program Files\Java\jre7\bin\javaw.exe" -jar "full path to minecraft.exe"

Sound

 * x Unchecked volume increase? Placing a water source at the feet of 500+ mobs standing in a single square produces a very loud sound equivalent to a small army of creepers detonating simultaneously.
 * ? Rain does not always generate the rain sound.
 * x Walking across a series of trapdoors does not make any sounds. Walking across the edges of blocks adjacent to the trapdoors (ie, walking across the top of the block containing the trapdoor) makes the walking on wood sound.
 * ? chest do not make opening or closing sound next to stone blocks.

Weather

 * x Sometimes a thunderstorm can start but it will not rain until near the end of the storm. Mobs spawn normally.
 * a Weather sounds/looks the same regardless of weather severity. Would be nice to be able to distinguish audio/visually between an overcast day, a light drizzle and "Get the **** out of this!" weather. Thundersnows and Desert Lightning.

Lava

 * ? While in the Nether, I fell into the lava. I paused the game (with esc) but after a few seconds, the entire screen went completely red and the game froze. I had to end the process to get rid of it. (If you want to recreate my scenario for testing purposes, I was wearing full Iron armor at the time, if that matters.)
 * f You can now create an infinite lava spring.

Water

 * ! if you have a column of water running down a wall and you block the hole, the water below it keeps flowing, it's like all the water becomes source blocks. //Confirmed, water placed above air will turn all blocks below into source blocks. This makes it impossible to have 1x1 flows of water because the source blocks will leak in all directions.
 * a Fluids such as water can alter other fluids to change their angle; however the angle of the water can alter whether or not an entity can jump out of the water. (Further explanation: Prior to 1.6 this feature didn't affect the way the water reacted with entities.  Current tests to exploit the angles of waters in all 4 directions when water was applied to corners or head on to shift the angle caused varied results.  For instance, it is impossible to jump out of a source block onto any other source blocks 1 block higher.  Using flowing water yielded a rather varied slew of results.  With just water straight ahead in the direction being tested, only West was able to hop out into the source block.  With water applied to the corners of a flowing stream to lift it up, 2 directions could hop out onto a dry block just fine while the other two could not.  All tests were done on the player, but I noticed these problems several months ago on a mob machine and did a slew of tests using mobs to gather the same odd results.)
 * x Placing a contained water source next to a ladder then carving the block below the ladder and placing a source block in that position will cause the first source block (the one next to the ladder, not under it) to convert into a flowing stream that points at the ladder; or rather the source block hidden in the hole below the ladder. Unsure which the game is doing since they are both in the same direction using this trick.  Basically it turns a source block into a flowing block when it shouldn't.
 * !a Water doesn't push activated TNT or minecarts.
 * !a Falling water destroys items normally pushed aside by flowing water. An exhaustive list: Sapling, powered rail, detector rail, cobweb, tall grass, dandelion, rose, brown mushroom, red mushroom, torch, redstone wire, seeds, rails, lever, redstone torches, button, redstone repeaters, stems, lily pads, nether warts, and other objects of similar nature.
 * x Tunneling up into the side of a body of water, finding yourself in a 1x1 waterfall and placing a block above to block the water caused no clipping (limited to the horizontal plane). Possible to move into blocks (causing suffocation) and resolved be quitting the entire client and restarting (exiting and reentering world does not resolve it). Probably an F6 issue

Biomes/Dimensions

 * ? Sometimes there are random cacti on mountains.
 * ?! Nether fortresses are not spawning (checked on 2 worlds using MCedit to check every part of the currently generated map for them. More extensive testing may be required.)
 * Make sure your MC Edit is up to date -- May just be generating an older version of Minecraft that doesn't have the Fortresses
 * They do spawn... I found two of them on my world in 350 block radius from my spawn position (Nether portal)
 * Sometimes a Biome with water such as an ocean or so, from a earlier version like 1.8/1.7.5 etc. will make the whole map into an Snow/ice Biome.
 * In my case, my whole 1.7.5 map turned into a snow / ice biome -_- and all the water froze and snow is on every block.
 * x Where Minecraft thinks the biome area is seems to have shifted, for example, the darker color of water from a nearby swamp biome has moved into the desert and now water there is that color, it also rains in some areas of the desert now
 * xA Strongholds almost always have mineshafts or canyons generated through them, usually taking out large chunks of what would have been the stronghold.

= References =