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Known bugs for Weekly Build 12w01a.

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.


There is no need to place bullet points before issue labels. Use bullet points only for comments. Be sure to leave a single totally blank line before each new issue (but not before comments), unless the issue appears directly beneath a header.

Please ensure that the bug is tested on a 'vanilla', installation of 12w01a with NO MODS installed

Please specify whether the bug was found on Single Player or Multi Player and Survival or Creative.

Please mark your issue with one of these issue labels: (listed from highest priority to lowest)

  • [!!] = {{bl|!!}} = Critical bug that can crash a Minecraft client or server.
  • [!] = {{bl|!}} = Major bug. Use this tag sparingly; if there is consensus your bug is not major, it will be downgraded.
  • [A!] = {{bl|a!}} = Major annoyance. Think very carefully before flagging an annoyance as major. Is it really more important than most minor bugs? Use this tag sparingly; if there is consensus your annoyance is not major, it will be downgraded.
  • [X] = {{bl}} = Minor bug.
  • [A] = {{bl|a}} = Annoyance.
  • [?] = {{bl|?}} = Potential issue that you are unsure of or that the community (on the discussion page) believes requires further vetting. Note: do not use this label to indicate this-is-not-a-bug; instead, replace the issue's current label with [A] or [A!]. Furthermore, it is inappropriate to use this to flag something you disagree with; instead, express your opinion in a comment. When you apply this label to an issue, place it after the issue's existing labels; do not remove those labels.

Labels for indicating that an issue happens only in a particular game mode: (These labels cannot stand alone; you must use them in addition to, not instead of, the ones listed above.)

  • [SP] = {{bl|sp}} = Single-player.
  • [MP] = {{bl|mp}} = Multiplayer.
  • [Su] = {{bl|su}} = Survival mode.
  • [Cr] = {{bl|cr}} = Creative mode.

Labels for indicating that an issue is restricted to a particular OS:

  • macOS = {{OS|OSX}} = Mac OS
  • Windows = {{OS|Win}} = Windows
  • Linux = {{OS|Linux}} = Linux

Labels that Mojang uses:

  • [F] = Bugs that have been fixed in the next update.
  • [N] = This is not a bug. (It is intended behaviour and will not be changed)
  • [S] = Bugs that will be skipped/ignored for now.
  • [U] = Bugs that Mojang tested but was unable to reproduce. Append this tag to the end of existing issue labels, instead of replacing them.

To produce these labels, use the following code: {{bl|c}} where c is the code of the label you wish to use. (e.g., a for annoyances, etc.)

The default issue type is minor bug; you can produce this label with the shorthand {{bl}}.

Be sure to sort issues by category, type, and priority: redstone issues go in the Redstone section, etc.; bugs go in the Bugs subsection, with major bugs listed before minor bugs, annoyances in the Annoyances subsection, with major ones before minor ones, and issues that Jeb has marked as fixed or skipped are moved to the Fixed/Skipped section. Issues that Jeb cannot reproduce, however, are to remain in their original place.

Please sign all issue reports and comments by typing ~~~ (three tildes; tilde may be found above Tab ↹ on USA keyboards, and to the right of @ on British keyboards).

Finally, please do not spontaneously delete an issue report or comment, unless it is patent nonsense submitted by someone who has not logged in. If possible, contact the submitter by user-talk first and tell them about your concerns. They will almost certainly oblige. As always, assume good faith.

Critical bugs[]


[!!] Game crashes on startup on some systems, despite not having done so on previous versions.

[!!] GPU overheating: on "Balanced" and "Max FPS" game runs on much more FPS than previous versions, causing GPU to sometimes overheat. On 1.0.0 I got barely 120 FPS on "Max FPS" setting, here on "Balanced" I get very close to 200, and temperature of GPU skyrockets, causing system shutdown. Only way to avoid it is to play at "Power Saver" which caps FPS around 40.

[!] Death in creative flat world (by falling to the void) will restart the world.

  • You restart in the same world but with different coordinates --Snybi
  • If you fall into void once, the second time you will respawn at the same place --{{static link|User:Akxei]

[!] Death in superflat type world changes spawn point (unless bed is used). --Nathan2055



[X] The "Sniper Duel" achievement does not register when completed.


[A] The Nether and The End in superflat generates normally.




[X] []= block ()=piston 0=space _= redstone != redstone torch

() ()__!


if you have done exactly as shown in the mini diagram the redstone will glitch out and will connect despite there being a piston block separating the two

[X] Zombies no longer swim upwards in source blocks.

[X] Zombie Pigmen will always attack you in the nether, even if you don't attack them.

[X] When wolves are put into "kennels" (which is represented just below) with the wolf in the middle, the wolf can get "stuck" in the block for a few seconds, dealing damage to the wolf through suffocation, the wolf will get up from sitting and run around for a few seconds.

                                            [ ]
                                          [ ]=[ ]

[X] zombies have longer reach on their first attack then they should. this extra reach is almost as long as the player's sword range. reach resets after the first hit delt to the player and returns back to proper length. Ninatiels 14:41, 6 January 2012 (UTC)

[X] Shift-click items doesn't work while Enchantment Table is opened.

[X] Zombies and Zombie-Pigmen spawned naturally in 12w01a worlds or spawned using the spawn egg cannot track the player when the player is more than 2 blocks above/below the zombie. (Test: in creative mode hit zombie then run up stairs. Zombie will stop following if you're too high. Same effect with flying.)

  • confirmed in SSP. zombie would come closer to me, but when it fell a couple blocks down it was too low to notice me and stopped following untill ig jumped up high enough again. also differant zombie wouldnt try to walk across lava to come after me or walk off cliff to try to chase me. perhapse they worked on pathfinding and the loss of tracking is a result? Ninatiels 23:27, 10 January 2012 (UTC)

[X] Zombies spawned naturally in worlds created in 1.0.0 or prior exhibit different behavior than zombies spawned with the spawn egg. For example, naturally spawned zombies can swim up in water source blocks, egg spawned zombies cannot. In worlds created in 12w01a, both egg-spawned and naturally-spawned zombies behave the same.

[X] Baby Animals don't follow wheat correctly (confirmed after multiple tries). --Nathan2055

  • Are they supposed to? --Gitterrost4
  • I thought only mobs which can breed follow wheat. --NeonJ

[X] No hostile mobs swin upwards in water source blocks (Miraboa)

[X] Slimes and Magma Cubes head f=0, when on creative mode

[X] there is a discrepancy in the health (or, some have suggested "armour") of Zombies and Zombie Pigmen, both of which now need 22 punches to be killed, rather than 20 punches.


[A] Slimes spawn very often in superflat worlds, possibly making them a bit too abundant





[A] Piston gets double headed. File:stickypictondoublehead.png


[X] Tall grass spawns in the beaches, on top of sand blocks

[X] Experience orbs fall through ice

[X] Created a new creative, superflat world with random seed. I found a few chunks who look like generated by the normal world generator.

  • Unable to recreate issue (tested on Mac OS X). More likely this is caused by previously reported file system error during world gen.--Inertia
  • Unable to reproduce error using seed and options. ( Tested on Win 7 ) -- Minecraft5025

[A] sand blocks spawning in mid air or as ceilings. has existed for a long time. perhapse make the game update them about 1/2 second after they are generated, just to make sure they are not hovering like that? or some kind of internal check tht wont let them spawn without something beneath them? Ninatiels 14:45, 6 January 2012 (UTC)



[X] Placing a water block in the same space as a ladder deletes the ladder, rather than rejecting water placement or popping the ladder off.

[X] Can't get on slab from ladder below (in previous versions that was able):

_ = slab | = ladder # = block
_    _
#|  |#
#|  |#



[X] Windows [MP] [SP] [Su] Lighting error in mp ( also found in sp ), fixed when destroying top block of the error, updating the area.




  • When Eating mushroom stew you still hear munching sound instead of slurping