Anybody who logs on to my server, their minecraft crashes.

This is the error message:

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

Minecraft has stopped running because it encountered a problem; Exception in world tick

A full error report has been saved to C:\Users\User\AppData\Roaming\.minecraft\crash-reports\crash-2012-11-16_18.11.21-client.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 49719eee --------
Full report at:
C:\Users\User\AppData\Roaming\.minecraft\crash-reports\crash-2012-11-16_18.11.21-client.txt
Please show that file to Mojang, NOT just this screen!

Generated 16/11/12 18:11

-- Head --
Stacktrace:
	at zs.a(SourceFile:820)
	at axz.a(SourceFile:851)
	at du.a(SourceFile:135)
	at cg.b(SourceFile:349)
	at axz.d(SourceFile:80)

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [ayk['DarraghBurke'/168, l='MpServer', x=-481.26, y=68.62, z=118.12]]
	Chunk stats: MultiplayerChunkCache: 27
	Level seed: 0
	Level generator: ID 02 - largeBiomes, ver 0. Features enabled: false
	Level generator options: 
	Level spawn location: World: (9,64,-119), Chunk: (at 9,4,9 in 0,-8; contains blocks 0,0,-128 to 15,255,-113), Region: (0,-1; contains chunks 0,-32 to 31,-1, blocks 0,0,-512 to 511,255,-1)
	Level time: 81975194 game time, 81975194 day time
	Level dimension: 0
	Level storage version: 0x00000 - Unknown?
	Level weather: Rain time: 0 (now: false), thunder time: 0 (now: false)
	Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: false
	Forced entities: 12 total; [pe['Sheep'/184, l='MpServer', x=-525.78, y=68.00, z=119.38], px['item.item.arrow'/185, l='MpServer', x=-519.34, y=68.13, z=131.78], oz['Cow'/201, l='MpServer', x=-488.28, y=67.00, z=143.75], qn['Skeleton'/196, l='MpServer', x=-504.06, y=25.00, z=130.53], ayk['DarraghBurke'/168, l='MpServer', x=-481.26, y=68.62, z=118.12], oz['Cow'/182, l='MpServer', x=-517.03, y=68.00, z=98.13], px['item.item.arrow'/185, l='MpServer', x=-519.34, y=68.13, z=131.78], qp['Spider'/193, l='MpServer', x=-502.81, y=63.00, z=98.28], oz['Cow'/192, l='MpServer', x=-511.81, y=68.00, z=91.25], pe['Sheep'/183, l='MpServer', x=-526.16, y=68.00, z=110.28], qn['Skeleton'/195, l='MpServer', x=-500.56, y=25.00, z=131.78], qn['Skeleton'/194, l='MpServer', x=-503.50, y=25.00, z=131.84]]
	Retry entities: 0 total; []
Stacktrace:
	at ayh.a(SourceFile:290)
	at net.minecraft.client.Minecraft.l(SourceFile:1338)
	at net.minecraft.client.Minecraft.J(SourceFile:582)
	at net.minecraft.client.Minecraft.run(SourceFile:534)
	at java.lang.Thread.run(Unknown Source)

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [ayk['DarraghBurke'/168, l='MpServer', x=-481.26, y=68.62, z=118.12]]
	Chunk stats: MultiplayerChunkCache: 27
	Level seed: 0
	Level generator: ID 02 - largeBiomes, ver 0. Features enabled: false
	Level generator options: 
	Level spawn location: World: (9,64,-119), Chunk: (at 9,4,9 in 0,-8; contains blocks 0,0,-128 to 15,255,-113), Region: (0,-1; contains chunks 0,-32 to 31,-1, blocks 0,0,-512 to 511,255,-1)
	Level time: 81975194 game time, 81975194 day time
	Level dimension: 0
	Level storage version: 0x00000 - Unknown?
	Level weather: Rain time: 0 (now: false), thunder time: 0 (now: false)
	Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: false
	Forced entities: 12 total; [pe['Sheep'/184, l='MpServer', x=-525.78, y=68.00, z=119.38], px['item.item.arrow'/185, l='MpServer', x=-519.34, y=68.13, z=131.78], oz['Cow'/201, l='MpServer', x=-488.28, y=67.00, z=143.75], qn['Skeleton'/196, l='MpServer', x=-504.06, y=25.00, z=130.53], ayk['DarraghBurke'/168, l='MpServer', x=-481.26, y=68.62, z=118.12], oz['Cow'/182, l='MpServer', x=-517.03, y=68.00, z=98.13], px['item.item.arrow'/185, l='MpServer', x=-519.34, y=68.13, z=131.78], qp['Spider'/193, l='MpServer', x=-502.81, y=63.00, z=98.28], oz['Cow'/192, l='MpServer', x=-511.81, y=68.00, z=91.25], pe['Sheep'/183, l='MpServer', x=-526.16, y=68.00, z=110.28], qn['Skeleton'/195, l='MpServer', x=-500.56, y=25.00, z=131.78], qn['Skeleton'/194, l='MpServer', x=-503.50, y=25.00, z=131.84]]
	Retry entities: 0 total; []

-- System Details --
Details:
	Minecraft Version: 1.4.4
	Operating System: Windows 7 (amd64) version 6.1
	Java Version: 1.7.0_04, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 1478751640 bytes (1410 MB) / 1543503872 bytes (1472 MB) up to 2863333376 bytes (2730 MB)
	JVM Flags: 2 total; -Xmx3072m -Xms1536m
	AABB Pool Size: 21635 (1211560 bytes; 1 MB) allocated, 158 (8848 bytes; 0 MB) used
	Suspicious classes: No suspicious classes found.
	IntCache: cache: 0, tcache: 0, allocated: 3, tallocated: 71
	LWJGL: 2.4.2
	OpenGL: Intel(R) HD Graphics GL version 2.1.0 - Build 8.15.10.2622, Intel
	Is Modded: Probably not. Jar signature remains and client brand is untouched.
	Type: Client (map_client.txt)
	Texture Pack: Default
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 158 (8848 bytes; 0 MB) allocated, 33 (1848 bytes; 0 MB) used

java.lang.ArrayIndexOutOfBoundsException
	at zs.a(SourceFile:820)
	at axz.a(SourceFile:851)
	at du.a(SourceFile:135)
	at cg.b(SourceFile:349)
	at axz.d(SourceFile:80)
	at ayh.b(SourceFile:62)
	at net.minecraft.client.Minecraft.l(SourceFile:1331)
	at net.minecraft.client.Minecraft.J(SourceFile:582)
	at net.minecraft.client.Minecraft.run(SourceFile:534)
	at java.lang.Thread.run(Unknown Source)
--- END ERROR REPORT fb5b6244 ----------