java.lang.IllegalArgumentException: n must be positive
	at java.util.Random.nextInt(Unknown Source)
	at agm.a(SourceFile:176)
	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:778)
	at mi.c(SourceFile:95)
	at mi.d(SourceFile:108)
	at afn.e(SourceFile:311)

---- Minecraft Crash Report ----
// You're mean.

Time: 13/10/26 21:43
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:176)
	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:778)
	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:463)
	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:176)
	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:778)
	at mi.c(SourceFile:95)
	at mi.d(SourceFile:108)
	at afn.e(SourceFile:311)

-- Requested block coordinates --
Details:
	Found chunk: true
	Location: World: (-753,0,656), Chunk: (at 15,0,0 in -48,41; contains blocks -768,0,656 to -753,255,671), Region: (-2,1; contains chunks -64,32 to -33,63, blocks -1024,0,512 to -513,255,1023)
Stacktrace:
	at afn.a(SourceFile:249)
	at afn.e(SourceFile:477)
	at afn.d(SourceFile:463)
	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: (-753,0,655), Chunk: (at 15,0,15 in -48,40; contains blocks -768,0,640 to -753,255,655), Region: (-2,1; contains chunks -64,32 to -33,63, blocks -1024,0,512 to -513,255,1023)
Stacktrace:
	at mj.a(SourceFile:405)
	at mj.b(SourceFile:134)

-- Affected level --
Details:
	Level name: 新規ワールド
	All players: 1 total; [mm['tmisn'/396, l='新規ワールド', x=-542.53, y=9.00, z=652.88]]
	Chunk stats: ServerChunkCache: 578 Drop: 0
	Level seed: 7058248073944586795
	Level generator: ID 01 - flat, ver 0. Features enabled: false
	Level generator options: 2;8x12;2;stronghold,biome_1,village,decoration,dungeon,mineshaft
	Level spawn location: World: (-549,4,648), Chunk: (at 11,0,8 in -35,40; contains blocks -560,0,640 to -545,255,655), Region: (-2,1; contains chunks -64,32 to -33,63, blocks -1024,0,512 to -513,255,1023)
	Level time: 11287 game time, 11287 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 98032 (now: false), thunder time: 1278 (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 8 (amd64) version 6.2
	Java Version: 1.7.0_06, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 102483528 bytes (97 MB) / 954466304 bytes (910 MB) up to 954466304 bytes (910 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G
	AABB Pool Size: 414222 (23196432 bytes; 22 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: 227044 (12714464 bytes; 12 MB) allocated, 0 (0 bytes; 0 MB) used
	Player Count: 1 / 8; [mm['tmisn'/396, l='新規ワールド', x=-542.53, y=9.00, z=652.88]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.