---- Minecraft Crash Report ----
// Shall we play a game?

Time: 8/2/14 9:50 AM
Description: Exception in server tick loop

java.lang.IllegalArgumentException: n must be positive
	at java.util.Random.nextInt(Unknown Source)
	at arl.b(SourceFile:281)
	at arl.a(SourceFile:297)
	at arl.a(SourceFile:92)
	at arl.a(SourceFile:49)
	at aqz.a(SourceFile:388)
	at asa.a(SourceFile:85)
	at bfx.a(SourceFile:472)
	at qn.a(SourceFile:174)
	at bek.a(SourceFile:858)
	at qn.c(SourceFile:104)
	at net.minecraft.server.MinecraftServer.j(SourceFile:314)
	at cxc.a(SourceFile:111)
	at cxc.h(SourceFile:127)
	at net.minecraft.server.MinecraftServer.run(SourceFile:416)
	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 (x86) version 6.1
	Java Version: 1.7.0_65, Oracle Corporation
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
	Memory: 115286792 bytes (109 MB) / 220467200 bytes (210 MB) up to 523501568 bytes (499 MB)
	JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
	IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 105
	Profiler Position: N/A (disabled)
	Player Count: 0 / 8; []
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.