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-465143/

Crash:

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

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

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

Time: 10/25/13 8:11 AM
Description: Invalid Biome id

java.lang.NullPointerException: Invalid Biome id
	at agn.a(SourceFile:82)
	at agl.<init>(SourceFile:26)
	at agk.a(SourceFile:52)
	at agk.b(SourceFile:61)
	at agn.a(SourceFile:61)
	at aoj.a(SourceFile:933)
	at afn.a(SourceFile:116)
	at afn.a(SourceFile:1047)
	at bll.i(SourceFile:1328)
	at bll.a(SourceFile:919)
	at bll.b(SourceFile:813)
	at azd.ad(SourceFile:780)
	at azd.e(SourceFile:704)
	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 agn.a(SourceFile:82)

-- DownfallBlock --
Details:
	biome id: 0
	downfalls[] size: 256
	x: 0
	z: 0
	w: 16
	h: 16
Stacktrace:
	at agn.a(SourceFile:82)
	at agl.<init>(SourceFile:26)
	at agk.a(SourceFile:52)
	at agk.b(SourceFile:61)
	at agn.a(SourceFile:61)
	at aoj.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 afn.a(SourceFile:116)
	at afn.a(SourceFile:1047)
	at bll.i(SourceFile:1328)
	at bll.a(SourceFile:919)

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [bje['Caebcrafting'/164, 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: (229,64,367), Chunk: (at 5,4,15 in 14,22; contains blocks 224,0,352 to 239,255,367), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	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: survival (ID 0). Hardcore: false. Cheats: false
	Forced entities: 1 total; [bje['Caebcrafting'/164, 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 biz.a(SourceFile:284)
	at azd.b(SourceFile:1951)
	at azd.e(SourceFile:713)
	at net.minecraft.client.main.Main.main(SourceFile:103)

-- System Details --
Details:
	Minecraft Version: 1.7.2
	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: 113224960 bytes (107 MB) / 199114752 bytes (189 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: 21, allocated: 12, tallocated: 94
	Launched Version: 1.7.2
	LWJGL: 2.9.0
	OpenGL: AMD Radeon HD 6310 Graphics                      GL version 4.1.10834 Compatibility Profile Context, ATI Technologies Inc.
	Is Modded: Probably not. Jar signature remains and client brand is untouched.
	Type: Client (map_client.txt)
	Resource Packs: []
	Current Language: English (UK)
	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-465143/21336773/