Minecraft Wiki:Issues/1.2.3

Organization of This Page & Instructions
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.

If you're unsure of an issue, it's good practice to post about it on the talk page to see whether others can reproduce it. Make sure you're testing the bug in the correct version (for this page, that's 1.2.3) with no mods installed. Also, make sure to proofread your issue report before submitting it; unintelligible issue reports come off as inconsiderate and disrespectful. Finally, please determine which game mode(s) your issue appears in, and flag it with the appropriate label(s). (Also, note that if, for example, a minor annoyance appears in both single-player and multiplayer, and in both creative and survival modes, you should label it as [A], not [A][SP][MP][Su][Cr].)

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.

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Issue Labels
Please mark your issue with one of these issue labels: (listed from highest priority to lowest)
 * !! =  = Critical bug that can crash a Minecraft client or server.
 * ! =  = Major bug. Use this tag sparingly; if there is consensus your bug is not major, it will be downgraded.
 * 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.
 * undefined =  = Minor bug.
 * a =  = Annoyance.
 * ? =  = 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 =  = Single-player.
 * mp =  = Multiplayer.
 * su =  = Survival mode.
 * cr =  = Creative mode.

Labels for indicating that an issue is restricted to a particular OS:
 * =  = Mac OS X
 * =  = Windows
 * =  = GNU/Linux

Labels that Mojang (not you!) uses: (Please place these tags in front of existing issue labels; do not remove the existing labels.)
 * f = Issue for which a fix will appear in the next update.
 * n = Not a bug; intended behavior. By definition, this label is inapplicable to annoyances; annoyances are not bugs.
 * s = Issue that will not be fixed in the next update.
 * u = Issue that Mojang has tested but was unable to reproduce.

To produce these labels, use the following code:  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  undefined .

Crashing/System
Bugs !! after deleting minecraft.jar to get rid of mods i get on minecraft and it freezes at: updating minecraft. please help.
 * Usually, in order to fix this, you have to delete everything that is in the bin folder. It will then re-download everything.

a! 1.2.x is unplayable for me on "far" view distance: the game freezes up so much it's like ten seconds of freezing to one second of moving. On the F3 View the graph spikes right up to the top of the screen or off. I am playing with 32 bit Java and I have noted the warning, but there was no freezing or problems until MC 1.2. Is this just because of the new height limit and something I should accept? 90.211.114.219 16:46, 3 March 2012 (UTC)
 * From what I've gathered, it does seem to be mostly attributed to the height limit since it gets to render 128 more blocks per square. Still, I'm sure there will be fixes possible and hopefully soon. Hesuchia 19:06, 3 March 2012 (UTC)
 * I wrote about that as a major bug. "Minecraft is lagging heavily after playing for a few minutes. 0 FPS for 2-4 seconds with >1 sec delay between them. (SP, Normal/Far view distance)". It can be also related to the jungle biome - I have spawned near there. -- L.K.

! Game lags when in jungle biomes and/or around jungle trees.

!! Minecraft will not run with any form of Java 7
 * Apparently I have Java 7 installed and minecraft runs for me. ZuppaHD
 * Runs fine here, too. butterfly98901

!! Pressing the Open texture pack folder button in 1.2.3 will crash the game
 * Not for me (1.2.3), tried renaming texturepacks folder while minecraft was running, retried, still no crash. 194.137.243.226
 * I cannot reproduce this in 1.2.3 vanilla on Windows Vista Home Premium: freshly downloaded and installed, I login and click texture packs and click button "Open texture packs folder" and the expected Windows explorer folder opens. Please give the detailed error message and check your antivirus software in case that is the cause. -- Aurelius 15:28, 2 March 2012 (UTC)
 * Can you please pastebin the error it gives you? Or does the game just close with no error? Dinnerbone 15:55, 2 March 2012 (UTC)
 * I have this bug too. I used windows 7 with 64-bit Java. The game doesn't crash, it just freezes forever 217.120.203.3 18:49, 2 March 2012 (UTC)
 * To those reporting this problem: use a batch file to capture the java output and check the Event log (if on Windows) and post the details at the minecraftforum or the IRC channel at irc://irc.esper.net/MineCraftHelp so others can help diagnose the cause. Do the usual first: uninstall all Java and install only Java 6; set antivirus and firewall to allow java access to internet and to the %APPDATA% folder; if Windows, check the access permissions. -- Aurelius 12:34, 3 March 2012 (UTC)
 * Yes, that is exactly the problem: minecraft doesn't give an error, and doesn't crash (And yes I know how to run from batch). So I understand that you can't help without logs, I just wanted to say there are more people with this problem. 217.120.203.3 22:18, 3 March 2012 (UTC)
 * Vanilla Minecraft 1.2.3 with no mods? What operating system and Java version? Use a batch file setting APPDATA to make a completely clean install in a separate folder with nothing added and see if the problem reproduces. If it does then this has got to be a system issue, try make a new Windows profile and retest. -Aurelius 04:25, 4 March 2012 (UTC)


 * This sometimes happens to me. Instead of crashing, the game automatically closes without notice sometimes.
 * Can't reproduce on MC 1.2.3 vanilla and *original* Win 7 Professional 32-bit -- L.K.

!! Worlds made before Minecraft 1.2.2 become unplayable. Worlds made during 1.2.2 or after run smoothly.
 * Java and video drives are up to date. 75.106.37.15 21:44, 2 March 2012 (UTC)
 * Update: I don't know how to get the crash report. I wish that I did though. But I can tell you that I haven't used any mods, no world editors, and the world that I want to use was created in 12w8a, others go back to Beta 1.8. 75.106.37.15 02:39, 4 March 2012 (UTC)
 * Please define "unplayable".
 * Unplayable: During the loading of an older world, it states that it's "switching levels." Then the text disappears and goes to a black screen. 75.106.37.15 06:16, 3 March 2012 (UTC)


 * mp I am not the reporter of this bug, but I am having this issue with the server and ONLY the server version of 1.2.* I have a world from before 1.2 that when converted by the server code spits out this error on a player connecting. When converted for single player use it works perfectly fine. UPDATE: I seem to have discovered this is due to corrupted information in the player.dat file. I am reluctant to upload an example of this file because I do not know what is stored there. My best guess is that it is due to the use of the Multiverse bukkit plugin, as when the world was converted my user was not in the "normal" world. Deleting the relevant player.dat file allows the user to log back in.

[WARNING] Failed to handle packet: java.lang.NullPointerException java.lang.NullPointerException at je.c(SourceFile:102) at ht.b(SourceFile:127) at ht.a(SourceFile:38) at fj.a(SourceFile:94) at net.minecraft.server.MinecraftServer.w(SourceFile:435) at net.minecraft.server.MinecraftServer.run(SourceFile:356) at dm.run(SourceFile:490)
 * To those reporting problems converting pre-1.2.3 worlds please link to the affected world file, and if possible to its archive before it was converted, so that others can help diagnose the cause. Specify how the pre-1.2.3 world was created - which minecraft versions, options, which mods or world editors used. -Aurelius 12:34, 3 March 2012 (UTC)
 * Could you please reword this so that other people that have no idea what you're saying can understand it. 75.106.37.15 21:43, 3 March 2012 (UTC)
 * Zip the problem world folder from the /saves/ folder and upload it to a site such as mediafire, post the URL of the upload here or in a forum. Give details how the world was made, especially if mods or snapshots or prereleases were used in that world history. A mod or prerelease snapshot might have caused a problem. -Aurelius 04:34, 4 March 2012 (UTC)

N mp Setting server build limit to 64 will disallow creation of new blocks above 64, but does not prevent loading/generating blocks beyond 64. 194.137.243.226
 * But I think this is good, allows creating areas which are prohibited from modification. 194.137.243.226
 * This sounds like more of a feature than a bug to me. After all, it is called "build limit" and not "generation limit". I believe the intention of this limit is to inhibit player placed blocks only.CaMoreno3 18:21, 2 March 2012 (UTC)
 * Feature, not a bug: As of Server.properties : "max-build-height: The maximum height in which building is allowed. Terrain may still naturally generate above a low height limit. "

!! Maps in SMP tend to overload servers, causing annoying crashes of client and server.

!!mpwhen connecting to a server the client disconnects after 0-5 seconds giving a "connection reset by peer" error,occasionally gives up to 50 seconds before disconnecting happens only in 1.2.3 did not occur in the short window of 1.2.2 or 1.2

! Sometimes in Hardcore mode, if you jump into a ceiling, or walk into walls, you will go THROUGH the walls, and take damage. This also happens with doors, and torches, if you walk into them, you go into them, and take damage.
 * This sounds like an existing bug that happens when your sleep is interrupted by destruction of the bed, or something like that (I haven't seen it myself). It's not specific to Hardcore mode. kpreid

!! When converting (CNB's 3x3 Piston door map that I downloaded) old worlds the game crashes. Black Screen, "Saving Chunks" error does not show for game crashed as world started to convert. ZuppaHD

!! Silverfish spawning from being called out of their blocks crashes the game. (please confirm)ZuppaHD

! (commonly)  (rarely) At extremely low framerates (e.g. 4-6) it becomes impossible to use Mouse1 to attack/mine (brings up ingame menu) tested NOT mouse with a 2button PS/2 mouse. Indrora 04:23, 4 March 2012 (UTC)

Annoyances a!I tried to convert my flatgrass map to Anvil but it just blinks to the convert screen then shows an empty dirt background. After that it kicks me out of fullscreen and shows a black screen. Any ideas? Also I successfully converted all my other super-flat and normal worlds in about ten seconds. This is 1.2.2 and 1.2.3 with no mods and the map's files look identical to the other before conversion, right down to the individual files in each folder. EX: data has the maps and idcounts.dat etc.--Droid1134 01:16, 3 March 2012 (UTC)
 * Can you please try the same map (before conversion) in a multiplayer server, and see if it gives you any errors? Dinnerbone 04:45, 3 March 2012 (UTC)
 * Got this error: (Note: as a half-idea half-just to see if it worked, I did try deleting the top layer of the map; considering the huge bugs related to map height)

[INFO] Starting minecraft server version 1.2.3 [INFO] Loading properties [INFO] Starting Minecraft server on *:25565 [INFO] Preparing level "world" [INFO] Converting map! [SEVERE] Unexpected exception java.lang.ClassCastException: qx cannot be cast to nt 	at pf.g(SourceFile:113) at us.a(SourceFile:27) at ix.a(SourceFile:199) at ix.a(SourceFile:169) at ix.a(SourceFile:128) at net.minecraft.server.MinecraftServer.a(SourceFile:210) at net.minecraft.server.MinecraftServer.s(SourceFile:188) at net.minecraft.server.MinecraftServer.run(SourceFile:333) at dm.run(SourceFile:490) --Droid1134 22:37, 3 March 2012 (UTC)

a Neither 1.2.3 nor 1.2.2 accept command line arguments that previous versions accepted. I first determined this changed when the minecraft.jar launcher changed from 1.1 to 1.2.2, while the launcher for 1.2.3 is unchanged from 1.2.2. See Stand alone client (change). Please note this is not related to the environment variable JAVA_OPTIONS. -Aurelius 15:22, 2 March 2012 (UTC)

a Holding a map in hand and walking into a jungle biome in a multiplayer server will kick you from the server and produce the message "Internal Server Error". I've only tried it in multiplayer, not sure if it does this in singleplayer.
 * Can you please pastebin the error that is displayed on the server? Dinnerbone 04:34, 3 March 2012 (UTC)

a Starting minecraft in a terminal reveals that 1.2.3 still has a few debug messages. This would not be a problem except that in low-light areas (such as the Nether) a large number of messages similar to the following will scroll by as the player enters a new chunk: "Checking light -13, 14". This is a *huge* performance drain on lower-end systems. It can be somewhat mitigated by redirecting standard output to the bit bucket, i.e., java -Xmx2048M -Xms512M -cp minecraft.jar net.minecraft.LauncherFrame > /dev/null. There is still some performance lag with the light recalculation, but it's a minor stutter as compared to the slideshow without this workaround. --Benanov 06:01, 3 March 2012 (UTC)

amp Attempting to break the bottom half wooden door while standing in it will result in the door rapidly opening and closing. This can be fixed by moving out of the door.
 * Even if this didn't have a fix it's not a major annoyance --Moxxy 20:04, 3 March 2012 (UTC)

a under Java6-sun on Ubuntu (Untested on other distros) pressing "return to game" from the menu does **not** trap focus of mouse (Esc does though) Indrora 04:23, 4 March 2012 (UTC)

!! Alot of times when going into fullscreen, the game crashes, and leaves a crash report. The ammount of times this happens can be reduced when turning on Power Saver, but then it still happens. I do know this doesn't happen for everyone.

a  Cmd-Q don't work (should quit the program). Not even on main screen. 86.50.91.240 13:57, 4 March 2012 (UTC)

Redstone
Bugs

! Redstone does not power redstone placed below when placed on glowstone.
 * This is not considered a bug by many people, as it is more of a feature, allowing one-way redstone. -- Zugbug

a! Piston bug: stacking two pistons on top of each other (both pointed sideways), then powering the top one by placing a block on TOP of it with an active redstone wire, will power the top piston normally. If the block BELOW the 2-piston stack is removed, the bottom piston activates, and mysteriously receives power through the adjacent piston, from the wire 2-blocks away. Getting this bottom piston to turn off is nearly impossible, as replacing that block does not sever the ghost power source. The power is persistent: the bottom piston can be removed and replaced, and will immediately be powered. Powering/unpowering the bottom piston directly has no effect, and it cannot be retracted once glitched. Easily reproduced on two separate computers (in survival/creative single-player). --Tigerstripe
 * The phantom power seems to be related to the upper piston being extended: once glitched, the bottom piston can only be retracted once the top one is also retracted... so it's as if an extended piston's base transmits power vertically downward, as redstone wire does horizontally. --Tigerstripe
 * The piston is definitely glitched. I removed all blocks around the piston, and it floats in the air, extended. --Tigerstripe
 * Most likely an effect of the Piston Quasiconnectivity Bug --Variable

undefined A redstone torch placed one block over and one block above a slanted powered rail has no effect in 1.2.3. In 12w08a and previous versions this powers the rail.
 * A torch shouldn't be able to power a diagonally-adjacent block. If there's a bug here, it's that the rail was powered in previous versions. -- Orthotope

MPundefined When powering a redstone torch to turn it off and then unpowering it to turn it on it will sometimes begin to stay off until you replace it, however it will immediately repeat this behavior the moment it is powered again forcing the need to replace it each and every time until it is moved to a completely different location at least 5 blocks away from where it originally was set. This only seems to happen in Multiplayer as I have not been able to recreate it in Singleplayer.
 * A Redstone Torch should be powered when not powered and not powered when powered -- Cyan4235

Annoyances a In certain places some pistons will not shut off even after power is removed. It requires a block update to fix.

a When you quit and reload a game, redstone repeater loops freeze.

Blocks
Bugs

x Vines are replaced when a block is placed in the same space as them, like water, lava, snow, and grass. This is annoying and does not fit well with their new functionality.

x Like the above situation, this happens with long grass as well.

! The old bug with wrong tools for blocks. for instance pickaxe is quicker for removing wooden halfslabs --86.52.2.125 12:59, 3 March 2012 (UTC)

!! Previous world converted, now when placing blocks Minecraft crashes. When re-opened the block is still in your inventory and in the world. Only some worlds.
 * Error occurs to me as well but I relate this to a Lightning bug. I tested it with "Super Hostile - Spellbound Caves v1.1" see [Link]. Error Report in the description. --LordJakson 21:04, 2 March 2012 (UTC)
 * Confirmed on our map (SMP, converted from 1.1). While building a sculpture out of blocks, occasionally the client (and sometimes the server) crashes with "Internal server error".  When I log back in, the lighting is . . . odd looking, though I can't quite put my finger on what's wrong with it.  This has happened when placing cobble, pistons, and water from water buckets (the type of block may not be relevant).  In each case, I was placing blocks in a fairly confined space where the lighting calculations might be more complicated than normal, but I haven't looked at the lighting code since mid-Beta.  Haven't tried building on a 1.2-generated map; the players are somewhat invested in the current world.  Blahpers 20:55, 3 March 2012 (UTC)

!! (Unconfirmed/not thoroughly tested) Placing a torch (potentially other items?) on y=257 -- one block above the height limit -- is allowed, but in SMP causes an "Array out of bounds" exception and crashes all connected clients in addition to the server, requiring a server restart.
 * I actually created something similar in single player. Built tower to max height, placed water on top (technically above) and then replaced water with torch.  crashed immediately. (EDIT seems to have been fixed in 1.2.3)-- Kittani1977
 * Still reproducible on 1.2.3 SMP --Outi 09:51, 2 March 2012 (UTC)
 * (1.2.3 cmp,smp) I was able to place torch there, but no crash. 194.137.243.226
 * Please pastebin the full error you get so that I may investigate it. Dinnerbone 19:07, 2 March 2012 (UTC)

! Having a tower to the max height to 256 in the sky, and having a ladder on the side from 1-127 will show just fine, but 128-256 will be invisible. Breaking any one of the invisible ladders will cause all of the invisible ones to break and fall down as items. Visible ladders from 1-127 work just fine though.

undefined you can't grow birch and pine trees over 128 block high. oak and jungle tree grow just fine with both versions available.
 * I was able to grow both at 140+ with bonemeal, may have been repaired in 1.2.3 --Kittani1977
 * Was able to let natuarally grow all trees at above 128. A 2x2 jungle tree grew up to within 2 of the top level with bonemeal and a single jungle grew short to the same point in 1.2.3 -- Kittani1977

undefined Piston arms no longer are able to push the player in single player. can be "fixed" by shooting an arrow into an extended piston head in a nearby loaded chunk (effectively breaking compact 4x4 piston elevators)

! Jungle tree leaves rarely ever drop jungle saplings.
 * I believe this is because they only drop saplings when a player breaks them. Could someone confirm? Regdoug 23:42, 3 March 2012 (UTC)
 * No, they drop saplings regardless of whether being broken or decaying. I have been farming a lot of jungle trees for saplings, so I can say for certain that although the drop rate is low, it is definitely renewable (though it is a little annoying when I go through six trees and end up with one fewer sapling than when I started). -Thorny 09:38, 4 March 2012 (UTC)

a When block placed above tall grass, the grass will be replaced by that block. -jelmer1414
 * It's a feature. See Version_history 1.2.1: "Placing blocks on Grass will replace it." 91.51.179.105

xcr When a door is broken by clicking on the top half, the item drop appears. Breaking the door from the bottom doesn't do this, however.

x glowstone will not stop a chest from opening.(tested on windows 7)
 * As glowstone is not a solid block, I believe this is expected behavior. 109.246.254.186

Annoyances

a When you try walking on jungle leaves diagonally or near a hole, sometimes you will fall through the leaf, possibly dropping all the way down if there's nothing below it.

a You CAN press "Shift" when you're sleeping on bed.

a You cant place torches on the bottom of blocks
 * You're not supposed to be able to do that.

Crafting/Enchanting/Brewing/Interface
Bugs undefined A very old bug: When Lava Buckets are used as fuel for smelting, the bucket is consumed along with the lava.

u The first character of every enchantment label is missing. For example, "lame I" instead of "Flame I".
 * Grammar corrected for clarity. CaMoreno3 19:21, 1 March 2012 (UTC)
 * Appears to have been fixed in 1.2.3, but now cannot seem to get any enchantment to show up over 39 (EDIT: Been messing with it for a while to confirm.. it seems ok... but different... somone else is going to have to do this too. -- Kittani1977
 * Can't reproduce. If this happens again, please let me know what language you're using. Dinnerbone 01:16, 4 March 2012 (UTC)
 * The cause is from TooManyItems. Within 1 hour, Marglyph reuploaded the mod and addressed this. Goandgoo 01:48, 4 March 2012 (UTC)

undefinedSilk Touch doesn't work on Glass Blocks anymore.
 * If you mean Glass BLOCKS (result of smelting sand in a furnace) then this is a bug. If you meant Glass PANES (created by crafting 6 glass together in a workbench), then that is normal behavior. --Nathan2055 22:51, 2 March 2012 (UTC)
 * No, Silk Touch really doesn't work on glass blocks anymore. Almost certainly unintended, especially considering that Jeb wanted to take a look at ice functionality again.
 * On reddit Jeb found out about this and confirmed the glass thing is a bug.

undefinedEnchanted items in a minecart with chest lose their enchantment when the player "destroys" the minecart with chest.

Annoyances a! The enchanting system has always, and continues to be frustratingly unfair. sometimes producing Efficiency III when a level 50 enchant is used. Considering you need to kill NINE HUNDRED AND TWENTY FIVE zombies/creepers etc, to get to Level 50, users are naturally in consensus that, to quote Yahtzee Croshaw, the ratio of difficulty to find versus actual usefulness is completely arbitrary. While we respect the mystique Mojang have tried to create about enchanting, the numbers need serious review. Kizzycocoa a On some systems, pressing the mouse 4 or mouse 5 buttons on the side of the mouse will cause the Minecraft menu open.
 * Discussion moved to this page. Please comment on that page.

Gameplay
Bugs

! cr This old bug has been around for as long as Creative Mode itself. When flying in water or lava, horizontal movement is slowed to a crawl.

! Vertical momentum is maintained when traveling through an End Portal so falling into one can kill players in the End.

x mp Naturally generated leaves no longer decay in 1.2.3 tested in vanilla SMP
 * All naturally generated tree leave types decayed. (oak, large oak, birch, pine, jungle tree, 2x2 jungle tree, jungle undergrowth tree) (tested in cmp) Did this occur at 1.2.3 generated world or converted world? 194.137.243.226
 * It was a 1.2.3 generated world.

u Right-clicking with a water bucket will crash the game rarely. -FishSticks -Unable to reproduce
 * Could not reproduce with over 300 buckets placed in 1.2.3 -- Kittani1977
 * Can't reproduce. If it happens again, pastebin the error please. Dinnerbone 04:49, 3 March 2012 (UTC)

undefined While swimming through water surrounding blocks of water will turn to a darker shade of blue, these darker spots do no revert when you touch land and end up making the area look shoddy and generally ugly.
 * Does not appear to be happening in 1.2.3 -- Kittani1977

undefined Chests seem to get caught in an endless loop of opening and closing.
 * Could not reproduce in 1.2.3 -- Kittani1977
 * This is happening but may be multi-player only -- Alexander

undefined If you log out while sitting in a boat, you fall out of the boat when you log back in. 82.69.54.207

a Doors will not open for non-ops in vanilla SMP
 * Could not reproduce with 10 different players. was it inside the protected spawn area? ~Ramena

! mp Upgrading an unmodded SMP server from 1.1 caused the previously-developed Nether dimension to regenerate from scratch, destroying all player creations. Blahpers 21:32, 2 March 2012 (UTC)
 * Unconfirmed on a server I go on. We are an unmodded server, upgraded from 1.1, and our Nether is still intact. Zyn 22:15, 2 March 2012 (UTC)
 * Must be one of those fun intermittent bugs. There are several posts about this on minecraftforum.net regarding this behavior in 1.2.2.  Digging them up now. Blahpers 23:21, 2 March 2012 (UTC)
 * Here: http://www.minecraftforum.net/topic/1068277-nether-not-converted/ Blahpers 23:21, 2 March 2012 (UTC)
 * Confirmed on a modded server I go on. Additionally, the nether was very laggy, while the overworld wasn't.

a In SSP,the game seems to be laggier than it used to,but in SMP there's barely any lag.
 * This is a system issue, not a bug with Minecraft. --Nathan2055 22:51, 2 March 2012 (UTC)
 * I've had the same problem. However, I used to get around 90 to 120 FPS, now about 60. I also drop to the 30s when I look the directions f: 2 and f: 3 (like Minecraft's ingame compass without redstone if you press F3). However on some servers (ex. evocraft.net) get the average 80 when looking all ways) also looking up and down shoots my FPS up to 250 to 300. (1.2.2, 1.2.3) My seed is JUNGLEHUNT if you're wondering. Edit: It is a problem with jungles. If you are near or in a jungle, facing a few ways will cause you to drop in FPS a bit.

! sp When walking next to redstone repeaters in a room two blocks high you will sometimes fall through the floor, potentially resulting in death from lava, fall damage or suffocation. (This has been around for a while, but it still needs to be addressed.) Dendrite 23:56, 2 March 2012 (UTC)

replicate construction... x=block r=repeater 0=air y level 1 xxx xxx xxx y level 2 xr0 r00 000 y level 3 000 000 000 y level 4 000 0x0 000 Walk towards inside corner of two repeaters. Make sure you have 2 space bellow construction. 93.106.40.21

x If a minecart with a chest is shot with a bow (may also occur when destroyed normally), any enchanted items that were in the chest lose their enchantments when the contents of the chest spill out.

x Place one jungle sapling and three normal saplings in a 2x2 grid. Apply one bonemeal to jungle sapling. Nothing grows (as expected), but the normal saplings turn into jungle saplings when you break them. 67.255.2.214 07:03, 3 March 2012 (UTC)
 * Actually, this seems to be sporadic. Now a 2x2 tree grows when I apply bonemeal. 67.255.2.214 07:24, 3 March 2012 (UTC)

I can clarify this bug - if there is no room for the jungle tree to grow, you will get 4 jungle saplings back instead of what you planted. --Benanov 16:59, 3 March 2012 (UTC)

I recreated this bug. It just created a a huge jungle tree. I put the bone meal on the jungle sapling and it turned into a huge jungle tree.

! Opening a chest in single player while holding an in-game map deletes in-game map. Not tested in multiplayer.
 * Unable to reproduce. --Lolmaster 06:30, 4 March 2012 (UTC)

Annoyances

a! The player cannot sprint up stairs.

a jungle leaves on 2x2 trees start to decay as soon as they are planted
 * Can't confirm this. Planted 10 2x2 jungle trees and none of the leaves decayed
 * This is the furthest thing from being major. Downgraded, --Moxxy 20:04, 3 March 2012 (UTC)

a Dungeons generate much more often, and most often have only one chest. Yes, you can get more rare loot (saddles, cocoa beans, etc), but the monsters are extremely annoying hands down.
 * Major means it ruins your experience. Downgraded. --Moxxy 20:04, 3 March 2012 (UTC)

a When pressing F3, a graph shows up. It often happens that this graph is too large for me to see my coordinates, seed, biome, etc. The graph just takes too much space.

a You're not able to get to an Netherportal over the old build height (If you get into a Portal that is really high, move out of the Netherside Portal and go in again, it will spawn a completly new Portal on the ground.)

a When fire charges travel too far away from the player, they stop moving, but continue to exist in the same spot forever.

a The sound of rain still fails to play in Extreme Hills biomes. It is as if the lack-of-sound associated with snow is there by mistake. This has been an issue since at least 1.0 (the full release).

a! When colliding with soul sand in a boat, as soon as the player collision box crosses the soul sand collision box, the player will take fall damage equal the velocity at which the boat originally approached the soul sand. Easy to reproduce. Flagged major because soul sand as protection against boat destruction is a long-standing convention and death in situations where you wouldn't expect to die is kind of a deal breaker. --TQuin

Mobs
Bugs undefined sp as of the latest snapshot/1.2.3 npc's don't close doors anymore when you open them, making it possible for zombies to enter the house.

! Once the Enderdragon has been struck by the player once, it can no longer harm the player. This bug has been present for a long time. It can even be replicated in Creative mode, because the Enderdragon "repels" entities in a radius around itself until it is hit, at which point, the player can come in much closer.
 * Furthermore, Endermen have an extremely frequent tendency NOT to teleport, if the player strikes their legs repeatedly with a sword. This is a commonly utilized exploit, usually tossed about as "aiming for their legs". It makes defeating Endermen very easy.

! Very commonly hostile mobs show signs of peacefulness. They won't chase the player and simply walk around minding their own business. However, upon approaching to about two to three blocks away they turn aggressive and begin attacking. I've seen this bug occur with Zombies, Skeletons, and Creepers with 1.2.3 (the latest patch as of writing) installed. --Nathan2055 22:51, 2 March 2012 (UTC)

undefined When a Slime is red and starts emitting smoke, logging out of the client and logging back in will freeze the slime in it's current position, but it can still move. --Honeyblue 9:10, 3 March 2012 (EST)

undefined Occasionally Skeletons stop burning for a few seconds upon attacking them. Only confirmed with Skeletons with the latest patch (1.2.3) installed. --Nathan2055 22:51, 2 March 2012 (UTC)

undefined In 1.2.2 Snow golems do not place snow on the ground when wandering around at all.
 * Clarification: They do not place snow in plains, swamps or mushroom biomes. It's still unintended, and should be fixed.
 * Still do not in swamps in 1.2.3, haven't checked others. -- Kittani1977
 * Not only do they not produce snow in biomes where they are supposed to, but they die when it's snowing because the snow is counted as precipitation. *facepalm*

undefined Ocelots only spawn on easy or above difficulty only (Even though they are suppose to be peaceful mobs and don't harm you) Confirm?
 * I believe this due they spawned by mob generator. Read about that on weekly bug pages. (not tested) 194.137.243.226

undefined Iron golems do not spawn naturally.
 * Inaccurate. I have had iron golems spawn in my villages since the update.
 * Might be that they don't spawn in villages created before the current version. I've spent a lot of time in a village in one of my older worlds and have seen none.  Can anyone else confirm? --TQuin

a!When I updated to 1.2.2, I created a new world. I walked in one direction for a while and noticed a few wolves seemed to be following me. I thought this was odd but continued to walk. After a while, every step would bring a few more wolves. Soon, there were about 30. I wandered into a jungle and dug a small shelter, barely large enough for a bed, and wolves and ocelots soon filled the hole. It was almost impossible to move. After creating another new world, I wandered through a jungle and noticed piles of ocelots appearing inside leaf blocks. It's good that I had kept a backup of 1.1. Shortly after downgrading, I installed 1.2.3. I generated a new world and spawned next to a wolf. Immediately, every step would bring more wolves to me. I knew that this bug was not fixed so I downgraded again. 174.1.45.173 02:30, 3 March 2012 (UTC)

undefined When standing you stand in a portal with a block behind you creepers sometimes won't attack you.
 * Isn't that a good thing? Yoshidude56 17:48, 2 March 2012 (UTC)

? Not sure if this a bug, or an implemented feature, but in Singleplayer or SMP, Hostile Mobs do not spawn above level y: 240.6. This was tested on a newly generated world, and an old world converted to Anvil. - Dirtyfargo

undefined Some mobs that shouldn't be able to climb ladders (cows, pigs, sheep -- not chickens, as far as I can tell) can climb them anyway. --Chromium 19:12, 3 March 2012 (UTC)

undefined When a new Slime is spawned naturally or from an egg, xp drop is set to 4, 2 or 1 depending on its size - correct. But when it is loaded with a chunk or spawned from splitting, xp drop is a randomized (but still it's 4, 2 or 1) - incorrect. This bug also applies to Magma Cube. --mgr 23:22, 3 March 2012 (UTC)

undefined mp Large Slimes seem to have incorrect hitboxes at times, perhaps taking on the hitbox of a smaller size of slime. They can still hurt players from just as far away as their size of slime normally would be able to, which makes fighting these glitched large slimes very difficult.

Annoyances

a There is no way to choose which cat you get. You should be able to feed an ocelot different meats and the breed is determined by the meat. Siamese - fish, tuxedo - chicken, ginger - beef.

a Villagers are breeding incessantly.

a Ocelots are just untameable.
 * You might just be doing it wrong. Are you standing perfectly still? Do you give it fish when it walks up to you cautiously? Are you not looking around really fast? 69.141.106.13 17:53, 3 March 2012 (UTC) CoalSponge

a Villagers don't know how to climb ladders.

a Pigs are outclassed by cows right now because while pigs only drop 0-2 porkchops, cows drop 1-3 raw beef and are so much more useful in general. There is no good reason to farm pigs rather than cows, and pigs should at least be a reliable source of meat.
 * I agree that pigs should have a 1-3 drop rate, or cows should have a 0-2 drop rate. The two would also be more balanced if saddled pigs could be controlled in some manner.

a Iron Golems do not kill slimes. Slimes are annoying in superflat worlds and should be killed.


 * Slimes aren't just a nuisance, they're a blasted plague, but there are in-game workarounds to reduce the problem. I'll add a tip about it to the slime mob writeup 82.69.54.207


 * I believe this is for 2 reasons: One, the iron golem would be chasing too many slimes and eventually get out of range from the villagers, where they will not be protecting them. Two, they will be distracted by the slimes while villagers will be prone to zombie attacks.

World generator
Bugs

undefined Stronghold libraries do not have floors. They should have floors in the same way that abandoned mineshafts do. Right now I have not seen a single Stronghold library which had a floor. Sometimes there will also be no floor under iron doors, and when the button is pressed the door will fall.

! Village generation is very messy. Ravines, hills, and other stuff can ruin villages and doors can be blocked or stairless in a way that cuts villagers off from the rest of the village.

! Flat Worlds revert to "normal" when converted to Anvil, new chunks generate as "normal". http://i.imgur.com/mjV7v.jpg

undefined (1.2.3) Chunk generation error, chunk seems flipped. Seed "bug" (without ") location 41x,-381z. 194.137.243.226
 * Added picture Zicxynum 15:57, 2 March 2012 (UTC)
 * Unable to reproduce, running vanilla 1.2.3, using seed "bug" at exact location. Check for mods.
 * That seems to be a basin flooded by water...  Interesting...
 * Really? If this md5 12f6c4b1bdcc63f029e3c088a364b8e4, size 3 988 921 bytes, is not vanilla, I really liked to know. [this comment contains only description what is vanilla minecraft.jar] 194.137.243.226 EDIT:
 * My error. Looked at wrong hash. 12f6c... is the right one. [this comment contains only description what is vanilla minecraft.jar] 93.106.40.21 21:41, 2 March 2012 (UTC)
 * Doesn't look like an error to me, looks more like some really cool terrain generation. --Nathan2055 23:02, 2 March 2012 (UTC)
 * Is "12f6c" the seed, or is "bug" still the seed? Or is it "md5 12f6c4b1bdcc63f029e3c088a364b8e4"?
 * I can confirm this, but I don't think it's a bug. It just seems like a basin "chunk biome" filled with water.--Gibbl 14:06, 3 March 2012 (UTC)
 * I can confirm this also, and it is definately a bug. A jungle biome for me was cut with stripes of the old swamp biome after the convert. There were also "ghost blocks" in the swamp stripes. To fix just delete (or move) the .mcr backup file and leave the .mca anvil file.

undefined In 1.2, my Minecraft is generating excessive amounts of floating sand and even floating gravel in the overworld.

Annoyances a! Terrain generation has been changed again in 1.2. This caused huge issues in beta 1.8 and I had to delete my world because of really bad map corruption. Now, the same thing has happened and I am getting really sick of it.--Gibbl 13:59, 3 March 2012 (UTC)

a! Worlds in the first Minecraft save format (before McRegion) are no longer recognized by Minecraft and updated to the new format. This causes those worlds to be un-playable. I hope this can be fixed because I have several old worlds that I never bothered converting to McRegion that I would like to re-visit. NZguy 50.135.203.172

Graphical/Lighting
Bugs

x If a player skin has a head accessory, when sneaking, it will be offset 1 pixel up. Then, when looking down, the head will pass through the front face of it.

! When a layer of cobblestone or stone (presumably any other opaque block) is placed above a layer of ice which was created (in survival or hardcore mode) or placed (in creative mode) with nothing above it to the sky, the ice acts as a light source block but follows brightness levels with the day/night cycle as if the sky remains open above the block. Additional construction can take place above that block, and the light level does not change or vary except with weather and the day/night cycle. --Robert Horning 07:24, 3 March 2012 (UTC)

! Torches spawned in Mines and Villages will show incorrect lighting until updated. May not happen 100% of the time. (1.2.3 actually still does it)
 * This is a bug that has been around at least since 1.0. If you want proof, see this video (auto-linked to correct time). Upgrading to major bug. --Nathan2055 23:11, 2 March 2012 (UTC)

! When pressing the A-key on tiny render distance, it seems to force Minecraft to update the chuck in front of me. - Floedekage 10:17, 4 March 2012 (UTC)

undefined At times a texture will be stretched so that one of the corners is not on the actual block. Stretching may occur to a point far from the block. Observed on versions 1.1, 1.2.2 and 1.2.3

undefined Sometimes creating a closed in box when you place the final block light will still get through as if the block wasn't placed.

undefined If you surround an upside down slab with other blocks like this, it casts a shadow on the slab in the middle (makes sense for full blocks but not other upside down slabs)
 * I have noticed that if the blocks (upside-down slab) are 2xany its fine but as soon as you place 3xany shadows start to appear. Also torches placed directly under shadows does nothing. - Grey

undefined Players and mobs all seem to face towards f:0 in SMP - Happens in both 1.2.2 and 1.2.3 - Video of this occurring at http://www.youtube.com/watch?v=XXmoiu0gcrw - Lucifer_LLS

undefined There are light sources all over my super flat world. Some are inside blocks I've placed that are not normally light sources, some I've tracked down to be empty spaces, some floating. Additionally (possibly part of the same bug) some grass blocks are shaded while others are not, making an odd pattern. Windows 7 x64 with 64 bit Java.
 * Upgrading to bug. Can anybody reproduce this? --Nathan2055 23:11, 2 March 2012 (UTC)
 * On my server I have places getting shaded where blocks used to be, but currently have no blocks around them. On flat map.

undefined When placing a torch on the side of a block such that the air block it occupies is surrounded by blocks (eg:stone) on all sides except below it, said air block will appear un-lit, even though the torch is in it, the torch itself appears lit, and the torch still emits light to the surrounding blocks. Recorded on 1.2.3. -- Cyclone blaze ( user -  talk ) 17:34, 3 March 2012 (UTC)

Annoyances

a Nether void flickers very rapidly.
 * This is already a confirmed bug for some time now. It occurs when a thunderstorm is active in the Overworld. -- Cyclone blaze ( user -  talk ) 17:34, 3 March 2012 (UTC)

a Upside down stairs when positioned in a square amongst two normal stairs below to make a window frame does not allow light through. This making a normal sized square you can see out of but wont light up your room.
 * "Stair squares" don't let entities through, either. This includes arrows. :/

a There seems to be some lighting errors at chunk boundaries in SMP. Try fx the seed "21", and look at the sea bottom from above. Screenshot: http://thuejk.dk/minecraft1_2_lighting.png

a! Getting a lot of flicker in MC, seems to happen especially in MCP. No flicker in launcher, possible cause could be the allowance of more RAM by eclipse. 66.68.170.105 20:48, 3 March 2012 (UTC)
 * Found out what could be the problem, MC now has some issues when running in stand-alone mode. When running MC in standalone mode it now appears to update the screen independent of the location of it's container window. This means that in stand-alone mode (quit button is shown) that moving the window will not move minecraft until the user releases the mouse. This also causes a hefty amount of flicker, for some reason... This is also LWJGL Version independent66.68.170.105 21:37, 3 March 2012 (UTC)

Bugs
!!Putting ":" in the Direct Connect screen without the "s, it will crash the game upon attempting to connect.

! Player data may be randomly lost server-side, causing them to respawn at the default spawn without any items, with their spawn reset, and in the default game mode.

! It is possible for hostile mobs to become invincible, allowing them to hurt players without taking any damage from attacks or catching fire from the sun.

f Server is throwing error on connection:Failed to handle packet: java.lang.ArrayIndexOutOfBoundsException: 16
 * Deleting the player folder from the save folder will sometimes fix the problem.
 * Client side will say: Disconnected By Server, Internal Server Error.
 * Also happens when you die on the server.
 * No player can connect making the server useless.
 * Client must also be restarted after players folder is deleted, other wise the server will have to be restarted again.
 * Renaming the world directory or deleting the world directory may help. Removed a 1.2.2 generated world, restarted 1.2.3, players may now login.
 * This same error happens whenever an op builds above y=140 around the spawn point, which includes (-17, -17) to (17,17). Deleting the player dat files doesn't fix anything. The blocks above 140 have to be deleted, which can be done by opening the file in single player mode and copying the world back to SMP.

! Server throws severe java.lang.ArrayIndexOutOfBoundsException when "/gamemode playerName (any number above 1)" is used by an OP on the server.

! Some redstone wires do not update after using them after a while.
 * Mainly with torches.
 * Redstone is also causing massive lag spikes, seams to be realated.
 * Lag spikes can be large enough to crash client and sometimes server if large enough restone cicuts are running.

! Occasionally, "ghost", unusable items may show in the inventory. If they are moved, they just disappear. This is caused by the client thinking there's an item while the server does not.

! Several sound instances and animtations do not play:
 * Mob/Other Player arrow shooting sounds, snowball/egg/ender pearl/fishing rod throwing sounds.
 * Chicken egg laying sounds.
 * Pressure plate, lever, button sounds.
 * Mob/Other Player stepping sounds.
 * Other Player mining sounds (the sounds playing before the mining is finished - see Obsidian or Bedrock for examples).
 * Fishing rod sounds (reeling should not make a sound).
 * Cave sounds (or at least, they are not synchronized between players).
 * Slime/Magma Cube jumping animations.
 * Fishing rod "line".
 * Fishing rod "line" in held item. It shouldn't appear when the line is casted.
 * Other Player breaking animations.
 * Other Player enchantment animations (items/armor).

! Mining takes longer in multiplayer than in singleplayer. This is caused by a click-mining 'fix' that was added in Beta 1.3 and is not needed.

! Knockback and damage screen calculation is often wrong in multiplayer, actually dealing knockback when it shouldn't (like drowning or being on fire).

! Hitting mobs is harder in multiplayer because of lag. It is also much easier for monsters to hit players. Probably a delay before attacking (based on lag) should be added...

! Mobs, especially slimes and magma cubes, tend to bob up and down (being hard to hit) under low ceilings.
 * Slimes will often appear to teleport to the top of an overhang if they get under one and press up against a wall, which is really annoying because they can still hurt the player as though they are still on the ground and are pretty much invincible when they're doing this. In short, slimes can become practically invisible and invincible while maintaining their ability to damage players by pressing up against certain walls.

! Anvil's new per-chunk biome data is not sent in SMP. See here: http://wiki.vg/Pre-release_protocol#Map_Chunk_.280x33.29

! On maps converted by the server, existing minecarts can not be clicked/mounted/destroyed. They can be pushed around. To reproduce:
 * Create map with server 1.1, join, place some rails an a minecart.
 * Convert with server 1.2.3, join, try to enter or destroy minecart. (Make sure you dont have a new minecart in your hands) --Draradech
 * I suspect this is related to the mob feeding/attacking glitch below. --Chromium 19:42, 3 March 2012 (UTC)
 * Explains your 2 sorts of chicken: untouchable are the ones converted from an old map, the others have spawned later. --Draradech
 * Also occurs with minecarts with chests
 * Also occurs with boats.
 * Glitched minecarts can be destroyed with lava. (have not attempted with boats)
 * Ouch! Its much worse than I thought. It has nothing to do with conversion. I assume it affects all entities. How to reproduce fully on 1.2.3:
 * Create a new map, join, place rails and a minecart. It can be ridden and attacked.
 * Logout, Login. Minecart can no longer be ridden or attacked. This is a major problem. --Draradech

undefined Player movement is not smoothed enough (the client does this) in fairly or very laggy conditions.

undefined The skeleton on top of the spider (Spider Jockey) seems to randomly move back and forth on the spider.

undefined Arrows "warp up" when shot on walls. They also disappear and become impossible to collect when shot on ceilings.

undefined Arrow shooting is buggy and sometimes "resets" the charging progress.

undefined Having trouble making dogs change from sitting position.
 * Some mobs appear to be occasionally untouchable; I've only observed this with chickens and dogs. The mob cannot be hit with a sword (although a bow and arrow still works) and cannot be fed wheat to breed them. Dogs cannot be fed, bred with each other or told to sit/stand. It should be noted that this bug has some sort of trigger which I'm not sure of; some chickens can be killed, some can't, and I cannot find the difference between the two. --Chromium 19:12, 3 March 2012 (UTC)

Annoyances
a Instead of saying "Outdated Server!" when going on a 1.1 server, it says:" Internal Exception: java.net.SocketException:Connection reset"

a When adding a server, if you come out of full screen mode, it will reset your server name from what you typed in to "Minecraft Server".