Constant Crash - Locked out of World

Minecraft Crash Report ----
// Quite honestly, I wouldn't worry myself about that.

Time: 7/24/14 1:17 AM
Description: Exception in server tick loop

java.lang.IllegalArgumentException: n must be positive
at java.util.Random.nextInt(Unknown Source)
at aqz.a(SourceFile:224)
at aqz.a(SourceFile:49)
at aqn.a(SourceFile:388)
at bfl.a(SourceFile:472)
at qj.a(SourceFile:178)
at bdy.a(SourceFile:863)
at qj.c(SourceFile:108)
at qi.<init>(SourceFile:39)
at qh.a(SourceFile:231)
at qh.a(SourceFile:407)
at sd.a(SourceFile:812)
at cwk.x(SourceFile:142)
at net.minecraft.server.MinecraftServer.run(SourceFile:430)
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: 14w30b
Operating System: Windows 7 (amd64) version 6.1
Java Version: 1.7.0_60, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 292274960 bytes (278 MB) / 475004928 bytes (453 MB) up to 1908932608 bytes (1820 MB)
JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx2G
IntCache: cache: 0, tcache: 7, allocated: 13, tallocated: 95
Profiler Position: N/A (disabled)
Player Count: 1 / 8; [qn['Joebb3'/603, l='Rebuilt Snapshot World', x=-0.50, y=240.00, z=-13.50]]
Type: Integrated Server (map_client.txt)
Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.