---- Minecraft Crash Report ----
// My bad.

Time: 23/12/12 1:50 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: Copy of Sphere
	All players: 0 total; []
	Chunk stats: ServerChunkCache: 626 Drop: 0
	Level seed: 266163122477615839
	Level generator: ID 02 - largeBiomes, ver 0. Features enabled: true
	Level generator options: 
	Level spawn location: World: (23,64,-11), Chunk: (at 7,4,5 in 1,-1; contains blocks 16,0,-16 to 31,255,-1), Region: (0,-1; contains chunks 0,-32 to 31,-1, blocks 0,0,-512 to 511,255,-1)
	Level time: 102808 game time, 1999 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 165562 (now: false), thunder time: 57035 (now: false)
	Level game mode: Game mode: creative (ID 1). 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 7 (x86) version 6.1
	Java Version: 1.7.0_07, Oracle Corporation
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
	Memory: 190267816 bytes (181 MB) / 519110656 bytes (495 MB) up to 1037959168 bytes (989 MB)
	JVM Flags: 2 total; -Xms512m -Xmx1024m
	AABB Pool Size: 19983 (1119048 bytes; 1 MB) allocated, 0 (0 bytes; 0 MB) used
	Suspicious classes: No suspicious classes found.
	IntCache: cache: 0, tcache: 0, allocated: 3, tallocated: 71
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 2264 (126784 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.