---- Minecraft Crash Report ----
// Hi. I'm Minecraft, and I'm a crashaholic.

Time: 12/27/12 6:02 PM
Description: Exception ticking world

java.util.ConcurrentModificationException
	at java.util.HashMap$HashIterator.nextEntry(Unknown Source)
	at java.util.HashMap$KeyIterator.next(Unknown Source)
	at yp.a(SourceFile:72)
	at in.b(SourceFile:113)
	at net.minecraft.server.MinecraftServer.r(SourceFile:736)
	at net.minecraft.server.MinecraftServer.q(SourceFile:679)
	at bdz.q(SourceFile:117)
	at net.minecraft.server.MinecraftServer.run(SourceFile:613)
	at fy.run(SourceFile:849)


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

-- Head --
Stacktrace:
	at java.util.HashMap$HashIterator.nextEntry(Unknown Source)
	at java.util.HashMap$KeyIterator.next(Unknown Source)
	at yp.a(SourceFile:72)
	at in.b(SourceFile:113)

-- Affected level --
Details:
	Level name: Survival
	All players: 0 total; []
	Chunk stats: ServerChunkCache: 625 Drop: 0
	Level seed: 3350317427459628209
	Level generator: ID 00 - default, ver 1. Features enabled: true
	Level generator options: 
	Level spawn location: World: (-228,64,108), Chunk: (at 12,4,12 in -15,6; contains blocks -240,0,96 to -225,255,111), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
	Level time: 6144021 game time, 6889667 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 68811 (now: false), thunder time: 7122 (now: false)
	Level game mode: Game mode: survival (ID 0). Hardcore: false. Cheats: true
Stacktrace:
	at net.minecraft.server.MinecraftServer.r(SourceFile:736)
	at net.minecraft.server.MinecraftServer.q(SourceFile:679)
	at bdz.q(SourceFile:117)
	at net.minecraft.server.MinecraftServer.run(SourceFile:613)
	at fy.run(SourceFile:849)

-- System Details --
Details:
	Minecraft Version: 1.4.6
	Operating System: Windows Vista (x86) version 6.0
	Java Version: 1.7.0_10, Oracle Corporation
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
	Memory: 698282400 bytes (665 MB) / 1037959168 bytes (989 MB) up to 1037959168 bytes (989 MB)
	JVM Flags: 3 total; -Xbootclasspath/a:C:\\PROGRA~1\\Java\\jre7\\lib\\deploy.jar;C:\\PROGRA~1\\Java\\jre7\\lib\\javaws.jar;C:\\PROGRA~1\\Java\\jre7\\lib\\plugin.jar -Xmx1g -Xms1024M
	AABB Pool Size: 145193 (8130808 bytes; 7 MB) allocated, 0 (0 bytes; 0 MB) used
	Suspicious classes: No suspicious classes found.
	IntCache: cache: 0, tcache: 0, allocated: 1, tallocated: 63
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 10136 (567616 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
	Player Count: 0 / 8; []
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.