Hopper: java.lang.NullPointerException: Invalid Biome id

This is an automatically generated report based from the following crash: http://hopper.minecraft.net/crashes/minecraft/MCX-389611/

Crash:

java.lang.NullPointerException: Invalid Biome id
	at agk.a(SourceFile:82)

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

---- Minecraft Crash Report ----
// I let you down. Sorry :(

Time: 17/10/13 21:08
Description: Invalid Biome id

java.lang.NullPointerException: Invalid Biome id
	at agk.a(SourceFile:82)
	at agi.<init>(SourceFile:26)
	at agh.a(SourceFile:52)
	at agh.b(SourceFile:61)
	at agk.a(SourceFile:61)
	at aoc.a(SourceFile:933)
	at afk.a(SourceFile:116)
	at afk.a(SourceFile:1047)
	at blc.i(SourceFile:1321)
	at blc.a(SourceFile:918)
	at blc.b(SourceFile:813)
	at ayw.ac(SourceFile:776)
	at ayw.e(SourceFile:700)
	at net.minecraft.client.main.Main.main(SourceFile:103)


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

-- Head --
Stacktrace:
	at agk.a(SourceFile:82)

-- DownfallBlock --
Details:
	biome id: 0
	downfalls[] size: 256
	x: 0
	z: 0
	w: 16
	h: 16
Stacktrace:
	at agk.a(SourceFile:82)
	at agi.<init>(SourceFile:26)
	at agh.a(SourceFile:52)
	at agh.b(SourceFile:61)
	at agk.a(SourceFile:61)
	at aoc.a(SourceFile:933)

-- Coordinates of biome request --
Details:
	Location: World: (8,0,8), Chunk: (at 8,0,8 in 0,0; contains blocks 0,0,0 to 15,255,15), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
Stacktrace:
	at afk.a(SourceFile:116)
	at afk.a(SourceFile:1047)
	at blc.i(SourceFile:1321)
	at blc.a(SourceFile:918)

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [biw['Cundert'/77, l='MpServer', x=8,50, y=66,62, z=8,50]]
	Chunk stats: MultiplayerChunkCache: 0, 0
	Level seed: 0
	Level generator: ID 00 - default, ver 1. Features enabled: false
	Level generator options: 
	Level spawn location: World: (70,64,-25), Chunk: (at 6,4,7 in 4,-2; contains blocks 64,0,-32 to 79,255,-17), Region: (0,-1; contains chunks 0,-32 to 31,-1, blocks 0,0,-512 to 511,255,-1)
	Level time: 0 game time, 0 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: 1 total; [biw['Cundert'/77, l='MpServer', x=8,50, y=66,62, z=8,50]]
	Retry entities: 0 total; []
	Server brand: vanilla
	Server type: Integrated singleplayer server
Stacktrace:
	at bir.a(SourceFile:284)
	at ayw.b(SourceFile:1928)
	at ayw.e(SourceFile:709)
	at net.minecraft.client.main.Main.main(SourceFile:103)

-- System Details --
Details:
	Minecraft Version: 13w42a
	Operating System: Windows 7 (x86) version 6.1
	Java Version: 1.6.0_35, Sun Microsystems Inc.
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode, sharing), Sun Microsystems Inc.
	Memory: 110555064 bytes (105 MB) / 191569920 bytes (182 MB) up to 518979584 bytes (494 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M
	AABB Pool Size: 4627 (259112 bytes; 0 MB) allocated, 4627 (259112 bytes; 0 MB) used
	IntCache: cache: 1, tcache: 23, allocated: 12, tallocated: 94
	Launched Version: 13w42a
	LWJGL: 2.9.0
	OpenGL: GeForce GT 610/PCIe/SSE2 GL version 4.3.0, NVIDIA Corporation
	Is Modded: Probably not. Jar signature remains and client brand is untouched.
	Type: Client (map_client.txt)
	Resource Packs: []
	Current Language: Español (España)
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 18 (1008 bytes; 0 MB) allocated, 18 (1008 bytes; 0 MB) used
	Anisotropic Filtering: Off (1)

You can see this full report at http://hopper.minecraft.net/crashes/minecraft/MCX-389611/18837214/