java.lang.IllegalArgumentException: n must be positive
	at java.util.Random.nextInt(Unknown Source)
	at agm.a(SourceFile:130)
	at agm.a(SourceFile:27)
	at agg.a(SourceFile:362)
	at ago.a(SourceFile:29)
	at apg.a(SourceFile:162)
	at mi.a(SourceFile:160)
	at aoj.a(SourceFile:775)
	at mi.c(SourceFile:95)
	at mi.d(SourceFile:108)
	at afn.e(SourceFile:311)

---- Minecraft Crash Report ----
// I bet Cylons wouldn't have this problem.

Time: 10/25/13 11:35 PM
Description: Exception getting block type in world

java.lang.IllegalArgumentException: n must be positive
	at java.util.Random.nextInt(Unknown Source)
	at agm.a(SourceFile:130)
	at agm.a(SourceFile:27)
	at agg.a(SourceFile:362)
	at ago.a(SourceFile:29)
	at apg.a(SourceFile:162)
	at mi.a(SourceFile:160)
	at aoj.a(SourceFile:775)
	at mi.c(SourceFile:95)
	at mi.d(SourceFile:108)
	at afn.e(SourceFile:311)
	at afn.a(SourceFile:249)
	at afn.e(SourceFile:477)
	at afn.d(SourceFile:459)
	at afn.c(SourceFile:428)
	at afn.d(SourceFile:337)
	at afn.f(SourceFile:390)
	at ajj.m(SourceFile:46)
	at ajj.a(SourceFile:35)
	at mj.a(SourceFile:405)
	at mj.b(SourceFile:134)
	at net.minecraft.server.MinecraftServer.u(SourceFile:503)
	at net.minecraft.server.MinecraftServer.t(SourceFile:441)
	at bsk.t(SourceFile:117)
	at net.minecraft.server.MinecraftServer.run(SourceFile:358)
	at ky.run(SourceFile:617)


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 agm.a(SourceFile:130)
	at agm.a(SourceFile:27)
	at agg.a(SourceFile:362)
	at ago.a(SourceFile:29)
	at apg.a(SourceFile:162)
	at mi.a(SourceFile:160)
	at aoj.a(SourceFile:775)
	at mi.c(SourceFile:95)
	at mi.d(SourceFile:108)
	at afn.e(SourceFile:311)

-- Requested block coordinates --
Details:
	Found chunk: true
	Location: World: (736,0,325), Chunk: (at 0,0,5 in 46,20; contains blocks 736,0,320 to 751,255,335), Region: (1,0; contains chunks 32,0 to 63,31, blocks 512,0,0 to 1023,255,511)
Stacktrace:
	at afn.a(SourceFile:249)
	at afn.e(SourceFile:477)
	at afn.d(SourceFile:459)
	at afn.c(SourceFile:428)
	at afn.d(SourceFile:337)
	at afn.f(SourceFile:390)
	at ajj.m(SourceFile:46)
	at ajj.a(SourceFile:35)

-- Block being ticked --
Details:
	Block type: ID #12 (tile.sand // alt)
	Block data value: 0 / 0x0 / 0b0000
	Block location: World: (735,0,325), Chunk: (at 15,0,5 in 45,20; contains blocks 720,0,320 to 735,255,335), Region: (1,0; contains chunks 32,0 to 63,31, blocks 512,0,0 to 1023,255,511)
Stacktrace:
	at mj.a(SourceFile:405)
	at mj.b(SourceFile:134)

-- Affected level --
Details:
	Level name: Euphrasia
	All players: 0 total; []
	Chunk stats: ServerChunkCache: 448 Drop: 0
	Level seed: 4330290552100397106
	Level generator: ID 01 - flat, ver 0. Features enabled: false
	Level generator options: 2;12;2;stronghold,biome_1,village,decoration,dungeon,mineshaft
	Level spawn location: World: (755,4,471), Chunk: (at 3,0,7 in 47,29; contains blocks 752,0,464 to 767,255,479), Region: (1,0; contains chunks 32,0 to 63,31, blocks 512,0,0 to 1023,255,511)
	Level time: 563 game time, 563 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 83284 (now: false), thunder time: 83732 (now: false)
	Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: true
Stacktrace:
	at net.minecraft.server.MinecraftServer.u(SourceFile:503)
	at net.minecraft.server.MinecraftServer.t(SourceFile:441)
	at bsk.t(SourceFile:117)
	at net.minecraft.server.MinecraftServer.run(SourceFile:358)
	at ky.run(SourceFile:617)

-- System Details --
Details:
	Minecraft Version: 1.7.2
	Operating System: Windows 7 (x86) version 6.1
	Java Version: 1.7.0_07, Oracle Corporation
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode, sharing), Oracle Corporation
	Memory: 243635688 bytes (232 MB) / 518979584 bytes (494 MB) up to 518979584 bytes (494 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M
	AABB Pool Size: 131434 (7360304 bytes; 7 MB) allocated, 0 (0 bytes; 0 MB) used
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 655 (36680 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
	Player Count: 0 / 8; []
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.