Exception while ticking a block

Minecraft has crashed!      
      ----------------------      

Minecraft has stopped running because it encountered a problem; Exception while ticking a block

A full error report has been saved to /Users/avrilwick/Library/Application Support/minecraft/crash-reports/crash-2013-04-28_09.26.54-server.txt - Please include a copy of that file (Not this screen!) if you report this crash to anyone; without it, they will not be able to help fix the crash :(



--- BEGIN ERROR REPORT 54b27761 --------
Full report at:
/Users/avrilwick/Library/Application Support/minecraft/crash-reports/crash-2013-04-28_09.26.54-server.txt
Please show that file to Mojang, NOT just this screen!

Generated 4/28/13 9:27 AM

-- Head --
Stacktrace:
	at aom.a(SourceFile:127)
	at abw.a(SourceFile:367)
	at aab.f(SourceFile:302)
	at anf.e(SourceFile:123)
	at anf.a(SourceFile:105)

-- Block being ticked --
Details:
	Block type: ID #8 (tile.water // anf)
	Block data value: 9 / 0x9 / 0b1001
	Block location: World: (-33,41,311), Chunk: (at 15,2,7 in -3,19; contains blocks -48,0,304 to -33,255,319), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
Stacktrace:
	at iz.a(SourceFile:430)
	at iz.b(SourceFile:142)

-- Affected level --
Details:
	Level name: New W
	All players: 1 total; [jc['BulllShark'/454, l='New W', x=46.07, y=46.14, z=384.04]]
	Chunk stats: ServerChunkCache: 751 Drop: 0
	Level seed: 3260100436054213183
	Level generator: ID 00 - default, ver 1. Features enabled: true
	Level generator options: 
	Level spawn location: World: (48,64,256), Chunk: (at 0,4,0 in 3,16; contains blocks 48,0,256 to 63,255,271), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Level time: 148927 game time, 178375 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 161208 (now: false), thunder time: 14331 (now: false)
	Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: false
Stacktrace:
	at net.minecraft.server.MinecraftServer.r(SourceFile:454)
	at net.minecraft.server.MinecraftServer.q(SourceFile:397)
	at bjh.q(SourceFile:122)
	at net.minecraft.server.MinecraftServer.run(SourceFile:331)
	at gp.run(SourceFile:573)

-- System Details --
Details:
	Minecraft Version: 1.5.1
	Operating System: Mac OS X (x86_64) version 10.6.8
	Java Version: 1.6.0_45, Apple Inc.
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Apple Inc.
	Memory: 470446464 bytes (448 MB) / 581435392 bytes (554 MB) up to 1065025536 bytes (1015 MB)
	JVM Flags: 3 total; -Xbootclasspath/a:/System/Library/PrivateFrameworks/JavaApplicationLauncher.framework/Resources/LauncherSupport.jar -Xms512M -Xmx1024M
	AABB Pool Size: 5672 (317632 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
	Suspicious classes: No suspicious classes found.
	IntCache: cache: 0, tcache: 0, allocated: 2, tallocated: 62
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 2262 (126672 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
	Player Count: 1 / 8; [jc['BulllShark'/454, l='New W', x=46.07, y=46.14, z=384.04]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.

java.lang.NullPointerException
	at aom.a(SourceFile:127)
	at abw.a(SourceFile:367)
	at aab.f(SourceFile:302)
	at anf.e(SourceFile:123)
	at anf.a(SourceFile:105)
	at iz.a(SourceFile:430)
	at iz.b(SourceFile:142)
	at net.minecraft.server.MinecraftServer.r(SourceFile:454)
	at net.minecraft.server.MinecraftServer.q(SourceFile:397)
	at bjh.q(SourceFile:122)
	at net.minecraft.server.MinecraftServer.run(SourceFile:331)
	at gp.run(SourceFile:573)
--- END ERROR REPORT 8a2bf189 ----------