I'm walking in my world and when I reach a certain area the game crashes. Here is the report:

---- Minecraft Crash Report ----
// Sorry

Time: 27/10/14 6:05 PM
Description: Exception ticking world

java.lang.IllegalArgumentException: n must be positive
at java.util.Random.nextInt(Unknown Source)
at arv.a(SourceFile:224)
at arv.a(SourceFile:49)
at arj.a(SourceFile:389)
at bgt.a(SourceFile:472)
at qt.a(SourceFile:174)
at bff.a(SourceFile:863)
at qt.c(SourceFile:104)
at qt.d(SourceFile:116)
at aqr.a(SourceFile:276)
at qu.h(SourceFile:327)
at qu.c(SourceFile:202)
at net.minecraft.server.MinecraftServer.A(SourceFile:600)
at net.minecraft.server.MinecraftServer.z(SourceFile:532)
at cyk.z(SourceFile:155)
at net.minecraft.server.MinecraftServer.run(SourceFile:448)
at java.lang.Thread.run(Unknown Source)

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 arv.a(SourceFile:224)
at arv.a(SourceFile:49)
at arj.a(SourceFile:389)
at bgt.a(SourceFile:472)
at qt.a(SourceFile:174)
at bff.a(SourceFile:863)
at qt.c(SourceFile:104)
at qt.d(SourceFile:116)
at aqr.a(SourceFile:276)
at qu.h(SourceFile:327)
at qu.c(SourceFile:202)

– Affected level –
Details:
Level name: Why do I keep Breathing?
All players: 1 total; [qx['blair678'/72, l='Why do I keep Breathing?', x=-160.26, y=77.00, z=1553.10]]
Chunk stats: ServerChunkCache: 995 Drop: 0
Level seed: 27594263
Level generator: ID 02 - largeBiomes, ver 0. Features enabled: false
Level generator options:
Level spawn location: 0.00,70.00,0.00 - World: (0,70,0), Chunk: (at 0,4,0 in 0,0; contains blocks 0,0,0 to 15,255,15), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
Level time: 1350496 game time, 15000 day time
Level dimension: 0
Level storage version: 0x04ABD - Anvil
Level weather: Rain time: 1 (now: false), thunder time: 1 (now: false)
Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: true
Stacktrace:
at net.minecraft.server.MinecraftServer.A(SourceFile:600)
at net.minecraft.server.MinecraftServer.z(SourceFile:532)
at cyk.z(SourceFile:155)
at net.minecraft.server.MinecraftServer.run(SourceFile:448)
at java.lang.Thread.run(Unknown Source)

– System Details –
Details:
Minecraft Version: 1.8.1-pre3
Operating System: Windows 7 (amd64) version 6.1
Java Version: 1.7.0_71, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 331129680 bytes (315 MB) / 508035072 bytes (484 MB) up to 954728448 bytes (910 MB)
JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G
IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 99
Profiler Position: N/A (disabled)
Player Count: 1 / 8; [qx['blair678'/72, l='Why do I keep Breathing?', x=-160.26, y=77.00, z=1553.10]]
Type: Integrated Server (map_client.txt)
Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.