Hopper: java.lang.ArrayIndexOutOfBoundsException: -7

This is an automatically generated report based from the following crash: http://hopper.minecraft.net/crashes/minecraft/MCX-190892/

Crash:

java.lang.ArrayIndexOutOfBoundsException: -7
	at b.a(SourceFile:330)
	at b.a(SourceFile:317)
	at abw.h(SourceFile:1237)
	at js.h(SourceFile:364)

The following is the first clean report made public about this crash:

---- Minecraft Crash Report ----
// Uh... Did I do that?

Time: 19/09/13 18:45
Description: Exception ticking world entities

java.lang.ArrayIndexOutOfBoundsException: -7
	at b.a(SourceFile:330)
	at b.a(SourceFile:317)
	at abw.h(SourceFile:1237)
	at js.h(SourceFile:364)
	at net.minecraft.server.MinecraftServer.t(SourceFile:471)
	at net.minecraft.server.MinecraftServer.s(SourceFile:406)
	at bkz.s(SourceFile:124)
	at net.minecraft.server.MinecraftServer.run(SourceFile:340)
	at hi.run(SourceFile:583)


A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

-- Head --
Stacktrace:
	at b.a(SourceFile:330)
	at b.a(SourceFile:317)
	at abw.h(SourceFile:1237)
	at js.h(SourceFile:364)

-- Affected level --
Details:
	Level name: kai
	All players: 1 total; [jv['kaithomas'/103808, l='kai', x=-1276.30, y=62.00, z=-11.72]]
	Chunk stats: ServerChunkCache: 1079 Drop: 0
	Level seed: -1488382952467489159
	Level generator: ID 00 - default, ver 1. Features enabled: true
	Level generator options: 
	Level spawn location: World: (-147,64,205), Chunk: (at 13,4,13 in -10,12; contains blocks -160,0,192 to -145,255,207), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
	Level time: 1644579 game time, 1887895 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 95954 (now: false), thunder time: 11311 (now: false)
	Level game mode: Game mode: survival (ID 0). Hardcore: false. Cheats: false
Stacktrace:
	at net.minecraft.server.MinecraftServer.t(SourceFile:471)
	at net.minecraft.server.MinecraftServer.s(SourceFile:406)
	at bkz.s(SourceFile:124)
	at net.minecraft.server.MinecraftServer.run(SourceFile:340)
	at hi.run(SourceFile:583)

-- System Details --
Details:
	Minecraft Version: 1.6.4
	Operating System: Windows 7 (x86) version 6.1
	Java Version: 1.7.0_25, Oracle Corporation
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode, sharing), Oracle Corporation
	Memory: 1353432 bytes (1 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: 58111 (3254216 bytes; 3 MB) allocated, 58111 (3254216 bytes; 3 MB) used
	Suspicious classes: No suspicious classes found.
	IntCache: cache: 0, tcache: 0, allocated: 3, tallocated: 63
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 7749040 (433946240 bytes; 413 MB) allocated, 7749040 (433946240 bytes; 413 MB) used
	Player Count: 1 / 8; [jv['kaithomas'/103808, l='kai', x=-1276.30, y=62.00, z=-11.72]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.

You can see this full report at http://hopper.minecraft.net/crashes/minecraft/MCX-190892/12395832/