---- Minecraft Crash Report ----
// You're mean.

Time: 2014-07-30 20:40
Description: Exception in server tick loop

java.util.ConcurrentModificationException
	at java.util.HashMap$HashIterator.nextEntry(Unknown Source)
	at java.util.HashMap$KeyIterator.next(Unknown Source)
	at qi.a(SourceFile:163)
	at net.minecraft.server.MinecraftServer.y(SourceFile:614)
	at pk.y(SourceFile:303)
	at net.minecraft.server.MinecraftServer.x(SourceFile:530)
	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:
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-- System Details --
Details:
	Minecraft Version: 14w31a
	Operating System: Windows 7 (amd64) version 6.1
	Java Version: 1.7.0_60, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 736643040 bytes (702 MB) / 1941962752 bytes (1852 MB) up to 2382364672 bytes (2272 MB)
	JVM Flags: 0 total; 
	IntCache: cache: 0, tcache: 0, allocated: 12, tallocated: 94
	Profiler Position: N/A (disabled)
	Player Count: 1 / 5; [qr['NicklasE99'/431, l='world', x=19950,43, y=56,00, z=-21347,82]]
	Is Modded: Unknown (can't tell)
	Type: Dedicated Server (map_server.txt)