java.lang.IllegalArgumentException: n must be positive
	at java.util.Random.nextInt(Unknown Source)
	at adu.a(SourceFile:121)
	at adu.a(SourceFile:26)
	at ado.a(SourceFile:350)
	at aej.a(SourceFile:74)
	at agb.a(SourceFile:433)
	at kc.a(SourceFile:156)
	at aey.a(SourceFile:774)
	at kc.c(SourceFile:93)
	at kc.d(SourceFile:104)
	at act.e(SourceFile:297)
	at kd.g(SourceFile:231)
	at kd.b(SourceFile:134)

---- Minecraft Crash Report ----
// Ooh. Shiny.

Time: 9/5/13 9:49 PM
Description: Exception ticking world

java.lang.IllegalArgumentException: n must be positive
	at java.util.Random.nextInt(Unknown Source)
	at adu.a(SourceFile:121)
	at adu.a(SourceFile:26)
	at ado.a(SourceFile:350)
	at aej.a(SourceFile:74)
	at agb.a(SourceFile:433)
	at kc.a(SourceFile:156)
	at aey.a(SourceFile:774)
	at kc.c(SourceFile:93)
	at kc.d(SourceFile:104)
	at act.e(SourceFile:297)
	at kd.g(SourceFile:231)
	at kd.b(SourceFile:134)
	at net.minecraft.server.MinecraftServer.t(SourceFile:455)
	at net.minecraft.server.MinecraftServer.s(SourceFile:398)
	at bng.s(SourceFile:124)
	at net.minecraft.server.MinecraftServer.run(SourceFile:332)
	at hs.run(SourceFile:575)


A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

-- Head --
Stacktrace:
	at java.util.Random.nextInt(Unknown Source)
	at adu.a(SourceFile:121)
	at adu.a(SourceFile:26)
	at ado.a(SourceFile:350)
	at aej.a(SourceFile:74)
	at agb.a(SourceFile:433)
	at kc.a(SourceFile:156)
	at aey.a(SourceFile:774)
	at kc.c(SourceFile:93)
	at kc.d(SourceFile:104)
	at act.e(SourceFile:297)
	at kd.g(SourceFile:231)
	at kd.b(SourceFile:134)

-- Affected level --
Details:
	Level name: New World
	All players: 1 total; [kg['Xibwxc57'/141, l='New World', x=29999900.50, y=100.50, z=1.50]]
	Chunk stats: ServerChunkCache: 941 Drop: 0
	Level seed: 3178123015255266331
	Level generator: ID 00 - default, ver 1. Features enabled: true
	Level generator options: 
	Level spawn location: World: (80,64,256), Chunk: (at 0,4,0 in 5,16; contains blocks 80,0,256 to 95,255,271), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Level time: 1528 game time, 1528 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 97607 (now: false), thunder time: 170475 (now: false)
	Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: true
Stacktrace:
	at net.minecraft.server.MinecraftServer.t(SourceFile:455)
	at net.minecraft.server.MinecraftServer.s(SourceFile:398)
	at bng.s(SourceFile:124)
	at net.minecraft.server.MinecraftServer.run(SourceFile:332)
	at hs.run(SourceFile:575)

-- System Details --
Details:
	Minecraft Version: 13w36a
	Operating System: Windows 8 (amd64) version 6.2
	Java Version: 1.7.0_21, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 294939424 bytes (281 MB) / 434765824 bytes (414 MB) up to 954466304 bytes (910 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G
	AABB Pool Size: 2423 (135688 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
	Suspicious classes: [com.ibm.icu.text.ArabicShapingException], [gnu.trove.TIntCollection], [gnu.trove.impl.HashFunctions, PrimeFinder], [gnu.trove.impl.hash.THash, TPrimitiveHash, TIntIntHash], [gnu.trove.iterator.TIterator, TAdvancingIterator, TIntIntIterator], [gnu.trove.map.TIntIntMap], [gnu.trove.map.hash.TIntIntHashMap], [gnu.trove.procedure.TIntIntProcedure], [gnu.trove.set.TIntSet]
	IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 95
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 9164 (513184 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
	Player Count: 1 / 8; [kg['Xibwxc57'/141, l='New World', x=29999900.50, y=100.50, z=1.50]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.