Hopper: java.lang.IllegalArgumentException: n must be positive

This is an automatically generated report based from the following crash: http://hopper.minecraft.net/crashes/minecraft/MCX-86199/

Crash:

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 aer.a(SourceFile:84)
	at agc.a(SourceFile:429)
	at kc.a(SourceFile:156)
	at aez.a(SourceFile:774)
	at kc.c(SourceFile:93)
	at kb.<init>(SourceFile:28)
	at ka.a(SourceFile:209)
	at ka.a(SourceFile:246)
	at hw.a(SourceFile:151)
	at hw.c(SourceFile:202)
	at hw.a(SourceFile:95)
	at bnq.b(SourceFile:73)
	at net.minecraft.server.MinecraftServer.t(SourceFile:481)
	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)

The following is the first clean report made public about this crash:

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

Time: 06/09/13 20.04
Description: Exception in server tick loop

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 aer.a(SourceFile:84)
	at agc.a(SourceFile:429)
	at kc.a(SourceFile:156)
	at aez.a(SourceFile:774)
	at kc.c(SourceFile:93)
	at kb.<init>(SourceFile:28)
	at ka.a(SourceFile:209)
	at ka.a(SourceFile:246)
	at hw.a(SourceFile:151)
	at hw.c(SourceFile:202)
	at hw.a(SourceFile:95)
	at bnq.b(SourceFile:73)
	at net.minecraft.server.MinecraftServer.t(SourceFile:481)
	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:
---------------------------------------------------------------------------------------

-- System Details --
Details:
	Minecraft Version: 13w36b
	Operating System: Windows 7 (x86) version 6.1
	Java Version: 1.7.0_25, Oracle Corporation
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode, sharing), Oracle Corporation
	Memory: 91849424 bytes (87 MB) / 270548992 bytes (258 MB) up to 518979584 bytes (494 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M
	AABB Pool Size: 2913 (163128 bytes; 0 MB) allocated, 2913 (163128 bytes; 0 MB) used
	IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 95
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 360 (20160 bytes; 0 MB) allocated, 360 (20160 bytes; 0 MB) used
	Player Count: 1 / 8; [kg['MasterBaku2003'/244, l='viva la 1.7', x=29999990,50, y=0,50, z=0,50]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.

You can see this full report at http://hopper.minecraft.net/crashes/minecraft/MCX-86199/8392674/