---- Minecraft Crash Report ----
// But it works on my machine.

Time: 1/08/14 2:30 AM
Description: Exception ticking world

java.util.ConcurrentModificationException
	at java.util.ArrayList$Itr.checkForComodification(Unknown Source)
	at java.util.ArrayList$Itr.next(Unknown Source)
	at aqh.a(SourceFile:2316)
	at aqt.a(SourceFile:73)
	at qo.c(SourceFile:182)
	at net.minecraft.server.MinecraftServer.y(SourceFile:598)
	at net.minecraft.server.MinecraftServer.x(SourceFile:530)
	at cxc.x(SourceFile:155)
	at net.minecraft.server.MinecraftServer.run(SourceFile:446)
	at java.lang.Thread.run(Unknown Source)


A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

-- Head --
Stacktrace:
	at java.util.ArrayList$Itr.checkForComodification(Unknown Source)
	at java.util.ArrayList$Itr.next(Unknown Source)
	at aqh.a(SourceFile:2316)
	at aqt.a(SourceFile:73)
	at qo.c(SourceFile:182)

-- Affected level --
Details:
	Level name: world
	All players: 1 total; [qr['tragictryhard'/227, l='world', x=-1112.25, y=63.50, z=-102.81]]
	Chunk stats: ServerChunkCache: 655 Drop: 0
	Level seed: 8214227725568113724
	Level generator: ID 00 - default, ver 1. Features enabled: true
	Level generator options: 
	Level spawn location: 256.00,64.00,248.00 - World: (256,64,248), Chunk: (at 0,4,8 in 16,15; contains blocks 256,0,240 to 271,255,255), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Level time: 13414286 game time, 13720528 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 17012 (now: false), thunder time: 130714 (now: false)
	Level game mode: Game mode: survival (ID 0). Hardcore: false. Cheats: false
Stacktrace:
	at net.minecraft.server.MinecraftServer.y(SourceFile:598)
	at net.minecraft.server.MinecraftServer.x(SourceFile:530)
	at cxc.x(SourceFile:155)
	at net.minecraft.server.MinecraftServer.run(SourceFile:446)
	at java.lang.Thread.run(Unknown Source)

-- System Details --
Details:
	Minecraft Version: 14w31a
	Operating System: Windows 7 (x86) version 6.1
	Java Version: 1.7.0_55, Oracle Corporation
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
	Memory: 39050152 bytes (37 MB) / 498835456 bytes (475 MB) up to 1037959168 bytes (989 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G
	IntCache: cache: 0, tcache: 0, allocated: 12, tallocated: 94
	Profiler Position: N/A (disabled)
	Player Count: 1 / 8; [qr['tragictryhard'/227, l='world', x=-1112.25, y=63.50, z=-102.81]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.