java.lang.IllegalArgumentException: n must be positive
	at java.util.Random.nextInt(Unknown Source)
	at agm.a(SourceFile:122)
	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:772)
	at mi.c(SourceFile:95)
	at mi.d(SourceFile:108)
	at afn.e(SourceFile:311)

---- Minecraft Crash Report ----
// Daisy, daisy...

Time: 25/10/13 16:17
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:122)
	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:772)
	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:458)
	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:122)
	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:772)
	at mi.c(SourceFile:95)
	at mi.d(SourceFile:108)
	at afn.e(SourceFile:311)

-- Requested block coordinates --
Details:
	Found chunk: true
	Location: World: (127,0,-1889), Chunk: (at 15,0,15 in 7,-119; contains blocks 112,0,-1904 to 127,255,-1889), Region: (0,-4; contains chunks 0,-128 to 31,-97, blocks 0,0,-2048 to 511,255,-1537)
Stacktrace:
	at afn.a(SourceFile:249)
	at afn.e(SourceFile:477)
	at afn.d(SourceFile:458)
	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: (128,0,-1889), Chunk: (at 0,0,15 in 8,-119; contains blocks 128,0,-1904 to 143,255,-1889), Region: (0,-4; contains chunks 0,-128 to 31,-97, blocks 0,0,-2048 to 511,255,-1537)
Stacktrace:
	at mj.a(SourceFile:405)
	at mj.b(SourceFile:134)

-- Affected level --
Details:
	Level name: aventura
	All players: 1 total; [mm['MinerT03'/16504, l='aventura', x=314,23, y=13,20, z=-1708,63]]
	Chunk stats: ServerChunkCache: 635 Drop: 0
	Level seed: -3558053911110241743
	Level generator: ID 01 - flat, ver 0. Features enabled: true
	Level generator options: 2;12;2;stronghold,biome_1,village,decoration,dungeon,mineshaft
	Level spawn location: World: (323,4,-1702), Chunk: (at 3,0,10 in 20,-107; contains blocks 320,0,-1712 to 335,255,-1697), Region: (0,-4; contains chunks 0,-128 to 31,-97, blocks 0,0,-2048 to 511,255,-1537)
	Level time: 398 game time, 398 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 61759 (now: false), thunder time: 52078 (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 XP (x86) version 5.1
	Java Version: 1.7.0_45, Oracle Corporation
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode, sharing), Oracle Corporation
	Memory: 209160928 bytes (199 MB) / 402833408 bytes (384 MB) up to 518979584 bytes (494 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M
	AABB Pool Size: 69879 (3913224 bytes; 3 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: 184 (10304 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
	Player Count: 1 / 8; [mm['MinerT03'/16504, l='aventura', x=314,23, y=13,20, z=-1708,63]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.