[23:59:58] [Server thread/INFO]: Saving and pausing game...
[23:59:58] [Server thread/INFO]: Saving chunks for level 'Nomad World 2'/Overworld
[23:59:58] [Server thread/INFO]: Saving chunks for level 'Nomad World 2'/Nether
[23:59:58] [Server thread/INFO]: Saving chunks for level 'Nomad World 2'/The End
[00:00:10] [Server thread/INFO]: Changing view distance to 2, from 6
[00:03:26] [Server thread/INFO]: infogulch has just earned the achievement [Librarian]
[00:03:26] [Client thread/INFO]: [CHAT] infogulch has just earned the achievement [Librarian]
[00:05:29] [Server thread/ERROR]: Encountered an unexpected exception
java.util.ConcurrentModificationException
	at java.util.HashMap$HashIterator.nextEntry(Unknown Source) ~[?:1.7.0_51]
	at java.util.HashMap$KeyIterator.next(Unknown Source) ~[?:1.7.0_51]
	at qi.a(SourceFile:163) ~[14w31a.jar:?]
	at net.minecraft.server.MinecraftServer.y(SourceFile:614) ~[14w31a.jar:?]
	at net.minecraft.server.MinecraftServer.x(SourceFile:530) ~[14w31a.jar:?]
	at cxc.x(SourceFile:155) ~[14w31a.jar:?]
	at net.minecraft.server.MinecraftServer.run(SourceFile:446) [14w31a.jar:?]
	at java.lang.Thread.run(Unknown Source) [?:1.7.0_51]
[00:05:29] [Server thread/ERROR]: This crash report has been saved to: C:\Users\Joe\AppData\Roaming\.minecraft\crash-reports\crash-2014-07-31_00.05.29-server.txt
[00:05:29] [Server thread/INFO]: Stopping server
[00:05:29] [Server thread/INFO]: Saving players
---- Minecraft Crash Report ----
// Hey, that tickles! Hehehe!

Time: 7/31/14 12:05 AM
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 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:
---------------------------------------------------------------------------------------

-- System Details --
Details:
	Minecraft Version: 14w31a
	Operating System: Windows 8 (amd64) version 6.2
	Java Version: 1.7.0_51, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 76570656 bytes (73 MB) / 1050673152 bytes (1002 MB) up to 1050673152 bytes (1002 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G
	IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 95
	Profiler Position: N/A (disabled)
	Player Count: 1 / 8; [qr['infogulch'/248, l='Nomad World 2', x=1753.34, y=70.42, z=-893.52]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.
[00:05:29] [Server thread/INFO]: infogulch lost connection: TextComponent{text='Server closed', siblings=[], style=Style{hasParent=false, color=null, bold=null, italic=null, underlined=null, obfuscated=null, clickEvent=null, hoverEvent=null, insertion=null}}