Had the same crash when placing my own head:
---- Minecraft Crash Report ---- // Hi. I'm Minecraft, and I'm a crashaholic. Time: 16/04/14 12:09 Description: Unexpected error java.util.ConcurrentModificationException at java.util.LinkedList$ListItr.checkForComodification(Unknown Source) at java.util.LinkedList$ListItr.next(Unknown Source) at com.google.common.collect.Iterators$9.next(Iterators.java:939) at com.google.common.collect.Iterators.addAll(Iterators.java:357) at com.google.common.collect.Lists.newArrayList(Lists.java:147) at oy.a(SourceFile:179) at oy.c(SourceFile:163) at oy.a(SourceFile:116) at att.d(SourceFile:88) at att.a(SourceFile:77) at ahf.a(SourceFile:79) at agh.a(SourceFile:122) at bqq.a(SourceFile:304) at bfr.ak(SourceFile:1256) at bfr.p(SourceFile:1602) at bfr.ai(SourceFile:801) at bfr.f(SourceFile:755) at net.minecraft.client.main.Main.main(SourceFile:121) A detailed walkthrough of the error, its code path and all known details is as follows: --------------------------------------------------------------------------------------- -- Head -- Stacktrace: at java.util.LinkedList$ListItr.checkForComodification(Unknown Source) at java.util.LinkedList$ListItr.next(Unknown Source) at com.google.common.collect.Iterators$9.next(Iterators.java:939) at com.google.common.collect.Iterators.addAll(Iterators.java:357) at com.google.common.collect.Lists.newArrayList(Lists.java:147) at oy.a(SourceFile:179) at oy.c(SourceFile:163) at oy.a(SourceFile:116) at att.d(SourceFile:88) at att.a(SourceFile:77) at ahf.a(SourceFile:79) at agh.a(SourceFile:122) at bqq.a(SourceFile:304) at bfr.ak(SourceFile:1256) -- Affected level -- Details: Level name: MpServer All players: 1 total; [bsv['Smurfy123Ringo'/63293, l='MpServer', x=-373.16, y=30.99, z=100.08]] Chunk stats: MultiplayerChunkCache: 121, 121 Level seed: 0 Level generator: ID 00 - default, ver 1. Features enabled: false Level generator options: Level spawn location: -255.00,64.00,29.00 - World: (-255,64,29), Chunk: (at 1,4,13 in -16,1; contains blocks -256,0,16 to -241,255,31), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511) Level time: 262508 game time, 262508 day time Level dimension: 0 Level storage version: 0x00000 - Unknown? Level weather: Rain time: 0 (now: true), thunder time: 0 (now: false) Level game mode: Game mode: survival (ID 0). Hardcore: false. Cheats: false Forced entities: 29 total; [ye['Sheep'/63113, l='MpServer', x=-329.84, y=64.00, z=23.22], zs['Creeper'/83937, l='MpServer', x=-386.81, y=31.00, z=97.78], za['item.item.egg'/95396, l='MpServer', x=-374.63, y=30.00, z=102.59], xu['Chicken'/94443, l='MpServer', x=-391.47, y=32.00, z=95.50], za['item.item.chickenRaw'/95398, l='MpServer', x=-373.22, y=30.00, z=99.78], ye['Sheep'/63128, l='MpServer', x=-317.09, y=65.00, z=21.13], ye['Sheep'/63127, l='MpServer', x=-310.69, y=62.00, z=27.47], aaz['Spider'/95403, l='MpServer', x=-299.50, y=66.00, z=29.50], ye['Sheep'/63138, l='MpServer', x=-311.81, y=61.00, z=32.25], bsv['Smurfy123Ringo'/63293, l='MpServer', x=-373.16, y=30.99, z=100.08], ye['Sheep'/63139, l='MpServer', x=-300.47, y=65.00, z=38.47], ye['Sheep'/63140, l='MpServer', x=-293.00, y=64.00, z=45.00], ye['Sheep'/63141, l='MpServer', x=-295.72, y=67.00, z=37.78], ye['Sheep'/63142, l='MpServer', x=-299.94, y=64.00, z=46.91], ye['Sheep'/63143, l='MpServer', x=-299.09, y=64.00, z=50.09], aar['Skeleton'/95472, l='MpServer', x=-414.50, y=72.00, z=89.50], bsw['VeryCosySlippers'/63915, l='MpServer', x=-336.16, y=33.00, z=-0.69], xu['Chicken'/94321, l='MpServer', x=-375.19, y=30.00, z=102.44], bsw['VeryCosySlippers'/63915, l='MpServer', x=-374.28, y=30.00, z=103.31], xu['Chicken'/94314, l='MpServer', x=-375.81, y=30.00, z=103.38], bsw['VeryCosySlippers'/63915, l='MpServer', x=-272.63, y=76.06, z=-15.72], zs['Creeper'/94187, l='MpServer', x=-359.59, y=32.00, z=95.94], ye['Sheep'/63093, l='MpServer', x=-335.75, y=64.00, z=21.44], ye['Sheep'/63094, l='MpServer', x=-365.09, y=65.00, z=21.09], ye['Sheep'/63095, l='MpServer', x=-375.88, y=66.00, z=28.03], ye['Sheep'/63102, l='MpServer', x=-358.81, y=69.00, z=42.59], ye['Sheep'/63103, l='MpServer', x=-349.50, y=69.00, z=44.50], ye['Sheep'/63098, l='MpServer', x=-355.22, y=69.00, z=42.59], ye['Sheep'/63099, l='MpServer', x=-357.94, y=70.00, z=38.91]] Retry entities: 0 total; [] Server brand: vanilla Server type: Integrated singleplayer server Stacktrace: at bqr.a(SourceFile:308) at bfr.b(SourceFile:2069) at bfr.f(SourceFile:769) at net.minecraft.client.main.Main.main(SourceFile:121) -- System Details -- Details: Minecraft Version: 14w11b Operating System: Windows 8 (amd64) version 6.2 Java Version: 1.7.0_51, Oracle Corporation Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation Memory: 206011048 bytes (196 MB) / 602931200 bytes (575 MB) up to 954728448 bytes (910 MB) JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 95 Launched Version: 14w11b LWJGL: 2.9.1 OpenGL: Intel(R) HD Graphics GL version 4.0.0 - Build 10.18.10.3282, Intel GL Caps: Using GL 1.3 multitexturing. Using GL 1.3 texture combiners. Using framebuffer objects because OpenGL 3.0 is supported and separate blending is supported. Anisotropic filtering is supported and maximum anisotropy is 16. Shaders are available because OpenGL 2.1 is supported. Is Modded: Probably not. Jar signature remains and client brand is untouched. Type: Client (map_client.txt) Resource Packs: [] Current Language: English (UK) Profiler Position: N/A (disabled) Anisotropic Filtering: Off (1)
Solomon Cammack
Had the same crash when placing my own head: