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 !! when i try to boot up minecraft it freezes for no reason and im playing 1.2.3 vanilla and a crash log doesn't come up at sit sits frozen for two hours so far

!! 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)

!! 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)
 * 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. If requested I can provide a link to the world files.

[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)

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

!! 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

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)

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)

A 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. "

Redstone
Bugs 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

Blocks
Bugs

! 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)

!! Attempting to place a sign on top of another sign at the top of the map crashes the game (tested in singleplayer and multiplayer).
 * I cannot reproduce this in singleplayer. In my vanilla 1.2.3 singleplayer any sign placed on top of a sign already at y=255 will not be placed and disappear from inventory. I tested placing signs on top of dirt, fence post, and torch. So far I tested these blocks placed at y=255 (note y coordinate is at the base of the placed block and not the avatar's eye level): seeds, torches, beds, signs, water. Please provide seed and coordinates and a link to the world file so that others can investigate. My screenshot: File:signaty255_v1_2_3.png. -Aurelius 13:13, 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)

!! (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.

a When block placed above tall grass, the grass will be replaced by that block. -jelmer1414

Crafting/Enchanting/Brewing/Interface
Bugs undefined 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
 * Could get roughly level 25 ench at max with 32 bookcases. Then added roof and floor bookcases, total 82 bookcases. After could get level 48 ench. Then removed back to 32 bookcases. Still could get level 48 ench. Rebuilt 32 bookcases + table, still could get level 48 ench. (did this in cmp) 194.137.243.226

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.

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

x mp Naturally generated leaves no longer decay in 1.2.3 tested in vanilla SMP *It was a 1.2.3 generated world.
 * 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

? 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)

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)

Annoyances

{A!} jungle leaves on 2x2 trees start to decay as soon as they are planted

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.

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.

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

Annoyances 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

World generator
Bugs

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)

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)

Graphical/Lighting
Bugs

! When a layer of cobblestone (presumably any other opaque block) is placed above a layer of ice, the ice acts as sunlight/moonlight (reflecting day/night cycle) and shines light to the room/layers below even if otherwise there is no other light source in that room (found when trying to build a spider grinder). Multiple layers of opaque blocks (only tested with cobblestone) above ice seem to continue behavior unless gaps are introduced between layers of opaque blocks. --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)

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.

Annoyances

a Nether void flickers very rapidly.

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

Bugs
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.
 * Clinet 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.

! Some redstone wires do not update after using them after a while.
 * Mainly with torches.

! Several sound instances 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).

! A few graphical elements are missing:
 * 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...

! 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)

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

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.

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