Hopper: java.lang.ArrayIndexOutOfBoundsException: 770

java.lang.ArrayIndexOutOfBoundsException: 770
	at aeg.a(SourceFile:123)

---- Minecraft Crash Report ----
// I'm sorry, Dave.

Time: 9/13/13 8:11 AM
Description: Invalid Biome id

java.lang.ArrayIndexOutOfBoundsException: 770
	at aeg.a(SourceFile:123)
	at agm.a(SourceFile:90)
	at agm.d(SourceFile:189)
	at kl.c(SourceFile:72)
	at kl.d(SourceFile:104)
	at add.e(SourceFile:311)
	at add.a(SourceFile:232)
	at adr.b(SourceFile:85)
	at adr.a(SourceFile:50)
	at jg.a(SourceFile:438)
	at jg.a(SourceFile:368)
	at kp.b(SourceFile:352)
	at ol.B(SourceFile:318)
	at pd.B(SourceFile:167)
	at ol.h(SourceFile:281)
	at pd.h(SourceFile:1171)
	at vf.h(SourceFile:205)
	at kp.i(SourceFile:197)
	at ku.a(SourceFile:195)
	at gm.a(SourceFile:136)
	at ea.b(SourceFile:64)
	at ku.e(SourceFile:63)
	at kx.b(SourceFile:37)
	at boc.b(SourceFile:84)
	at net.minecraft.server.MinecraftServer.u(SourceFile:483)
	at net.minecraft.server.MinecraftServer.t(SourceFile:400)
	at bnz.t(SourceFile:124)
	at net.minecraft.server.MinecraftServer.run(SourceFile:334)
	at jb.run(SourceFile:577)


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

-- Head --
Stacktrace:
	at aeg.a(SourceFile:123)

-- RawBiomeBlock --
Details:
	biomes[] size: 256
	x: -170
	z: 146
	w: 10
	h: 10
Stacktrace:
	at aeg.a(SourceFile:123)
	at agm.a(SourceFile:90)
	at agm.d(SourceFile:189)

-- Chunk to be generated --
Details:
	Location: -42,37
	Position hash: 163208757206
	Generator: RandomLevelSource
Stacktrace:
	at kl.c(SourceFile:72)
	at kl.d(SourceFile:104)
	at add.e(SourceFile:311)

-- Requested block coordinates --
Details:
	Found chunk: true
	Location: World: (-658,255,592), Chunk: (at 14,15,0 in -42,37; contains blocks -672,0,592 to -657,255,607), Region: (-2,1; contains chunks -64,32 to -33,63, blocks -1024,0,512 to -513,255,1023)
Stacktrace:
	at add.a(SourceFile:232)
	at adr.b(SourceFile:85)
	at adr.a(SourceFile:50)
	at jg.a(SourceFile:438)
	at jg.a(SourceFile:368)
	at kp.b(SourceFile:352)
	at ol.B(SourceFile:318)
	at pd.B(SourceFile:167)
	at ol.h(SourceFile:281)
	at pd.h(SourceFile:1171)
	at vf.h(SourceFile:205)

-- Player being ticked --
Details:
	Entity Type: null (kp)
	Entity ID: 41593
	Entity Name: JohnnyCheddar114
	Entity's Exact location: -530.00, 66.93, 554.00
	Entity's Block location: World: (-530,66,554), Chunk: (at 14,4,10 in -34,34; contains blocks -544,0,544 to -529,255,559), Region: (-2,1; contains chunks -64,32 to -33,63, blocks -1024,0,512 to -513,255,1023)
	Entity's Momentum: 0.00, 0.00, 0.00
Stacktrace:
	at kp.i(SourceFile:197)
	at ku.a(SourceFile:195)
	at gm.a(SourceFile:136)
	at ea.b(SourceFile:64)
	at ku.e(SourceFile:63)

-- Ticking connection --
Details:
	Connection: ku@5521b1d5
Stacktrace:
	at kx.b(SourceFile:37)
	at boc.b(SourceFile:84)
	at net.minecraft.server.MinecraftServer.u(SourceFile:483)
	at net.minecraft.server.MinecraftServer.t(SourceFile:400)
	at bnz.t(SourceFile:124)
	at net.minecraft.server.MinecraftServer.run(SourceFile:334)
	at jb.run(SourceFile:577)

-- System Details --
Details:
	Minecraft Version: 13w37b
	Operating System: Mac OS X (x86_64) version 10.6.8
	Java Version: 1.6.0_51, Apple Inc.
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Apple Inc.
	Memory: 311060144 bytes (296 MB) / 643248128 bytes (613 MB) up to 1065025536 bytes (1015 MB)
	JVM Flags: 1 total; -Xmx1G
	AABB Pool Size: 1865 (104440 bytes; 0 MB) allocated, 1590 (89040 bytes; 0 MB) used
	IntCache: cache: 0, tcache: 26, allocated: 13, tallocated: 95
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
	Player Count: 1 / 8; [kp['JohnnyCheddar114'/41593, l='New World', x=-530.00, y=66.93, z=554.00]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.