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

Time: 2/25/13 5:19 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: Flatest World In The World
	All players: 1 total; [iq['MuLv9001'/3677319, l='Flatest World In The World', x=431.50, y=45.50, z=21.50]]
	Chunk stats: ServerChunkCache: 1406 Drop: 0
	Level seed: -1999016167
	Level generator: ID 01 - flat, ver 0. Features enabled: true
	Level generator options: 2;2x4,3x3,2;1;biome_1,village
	Level spawn location: World: (-521,4,948), Chunk: (at 7,0,4 in -33,59; contains blocks -528,0,944 to -513,255,959), Region: (-2,1; contains chunks -64,32 to -33,63, blocks -1024,0,512 to -513,255,1023)
	Level time: 36206 game time, 5198 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 57641 (now: false), thunder time: 129203 (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_13, Oracle Corporation
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
	Memory: 460823096 bytes (439 MB) / 975540224 bytes (930 MB) up to 1037959168 bytes (989 MB)
	JVM Flags: 2 total; -Xms512m -Xmx1024m
	AABB Pool Size: 178 (9968 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
	Suspicious classes: No suspicious classes found.
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 20 (1120 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
	Player Count: 1 / 8; [iq['MuLv9001'/3677319, l='Flatest World In The World', x=431.50, y=45.50, z=21.50]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.