java.lang.IllegalArgumentException: n must be positive
	at java.util.Random.nextInt(Unknown Source)
	at adv.a(SourceFile:121)
	at adv.a(SourceFile:26)
	at adp.a(SourceFile:349)
	at ady.a(SourceFile:42)
	at agc.a(SourceFile:429)
	at kc.a(SourceFile:156)
	at aez.a(SourceFile:774)
	at kc.c(SourceFile:93)
	at kc.d(SourceFile:104)
	at act.e(SourceFile:311)
	at kd.g(SourceFile:231)
	at kd.b(SourceFile:134)

---- Minecraft Crash Report ----
// Don't do that.

Time: 06.09.13 18:28
Description: Exception ticking world

java.lang.IllegalArgumentException: n must be positive
	at java.util.Random.nextInt(Unknown Source)
	at adv.a(SourceFile:121)
	at adv.a(SourceFile:26)
	at adp.a(SourceFile:349)
	at ady.a(SourceFile:42)
	at agc.a(SourceFile:429)
	at kc.a(SourceFile:156)
	at aez.a(SourceFile:774)
	at kc.c(SourceFile:93)
	at kc.d(SourceFile:104)
	at act.e(SourceFile:311)
	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 bnn.s(SourceFile:124)
	at net.minecraft.server.MinecraftServer.run(SourceFile:332)
	at hr.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 adv.a(SourceFile:121)
	at adv.a(SourceFile:26)
	at adp.a(SourceFile:349)
	at ady.a(SourceFile:42)
	at agc.a(SourceFile:429)
	at kc.a(SourceFile:156)
	at aez.a(SourceFile:774)
	at kc.c(SourceFile:93)
	at kc.d(SourceFile:104)
	at act.e(SourceFile:311)
	at kd.g(SourceFile:231)
	at kd.b(SourceFile:134)

-- Affected level --
Details:
	Level name: 1.7
	All players: 1 total; [kg['Katze9'/292, l='1.7', x=29999899.50, y=100.50, z=0.50]]
	Chunk stats: ServerChunkCache: 1127 Drop: 0
	Level seed: 6788240468017160482
	Level generator: ID 00 - default, ver 1. Features enabled: true
	Level generator options: 
	Level spawn location: World: (198,64,247), Chunk: (at 6,4,7 in 12,15; contains blocks 192,0,240 to 207,255,255), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Level time: 16967 game time, 16967 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 21250 (now: false), thunder time: 11260 (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 bnn.s(SourceFile:124)
	at net.minecraft.server.MinecraftServer.run(SourceFile:332)
	at hr.run(SourceFile:575)

-- System Details --
Details:
	Minecraft Version: 13w36b
	Operating System: Windows 7 (amd64) version 6.1
	Java Version: 1.7.0_13, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 285394320 bytes (272 MB) / 1271070720 bytes (1212 MB) up to 8589934592 bytes (8192 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx9G
	AABB Pool Size: 5528 (309568 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
	IntCache: cache: 0, tcache: 0, allocated: 12, tallocated: 94
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 2062 (115472 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
	Player Count: 1 / 8; [kg['Katze9'/292, l='1.7', x=29999899.50, y=100.50, z=0.50]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.