Hopper: java.lang.NullPointerException

This is an automatically generated report based from the following crash: http://hopper.minecraft.net/crashes/minecraft/MCX-247438/

Crash:

java.lang.NullPointerException
	at aeh.a(SourceFile:82)

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

---- Minecraft Crash Report ----
// Don't be sad, have a hug! <3

Time: 27/09/13 13:59
Description: Invalid Biome id

java.lang.NullPointerException
	at aeh.a(SourceFile:82)
	at aef.<init>(SourceFile:26)
	at aee.a(SourceFile:52)
	at aee.b(SourceFile:61)
	at aeh.a(SourceFile:61)
	at alw.a(SourceFile:933)
	at adg.a(SourceFile:115)
	at adg.a(SourceFile:1040)
	at bik.i(SourceFile:1319)
	at bik.a(SourceFile:915)
	at bik.b(SourceFile:810)
	at awq.aa(SourceFile:781)
	at awq.e(SourceFile:704)
	at net.minecraft.client.main.Main.main(SourceFile:104)


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

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

-- DownfallBlock --
Details:
	downfalls[] size: 256
	x: 0
	z: 0
	w: 16
	h: 16
Stacktrace:
	at aeh.a(SourceFile:82)
	at aef.<init>(SourceFile:26)
	at aee.a(SourceFile:52)
	at aee.b(SourceFile:61)
	at aeh.a(SourceFile:61)
	at alw.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 adg.a(SourceFile:115)
	at adg.a(SourceFile:1040)
	at bik.i(SourceFile:1319)
	at bik.a(SourceFile:915)

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [bgi['Marstiphal'/175, 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: (48,64,256), Chunk: (at 0,4,0 in 3,16; contains blocks 48,0,256 to 63,255,271), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Level time: 20352 game time, 20352 day time
	Level dimension: 0
	Level storage version: 0x00000 - Unknown?
	Level weather: Rain time: 0 (now: true), thunder time: 0 (now: false)
	Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: false
	Forced entities: 1 total; [bgi['Marstiphal'/175, 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 bgd.a(SourceFile:301)
	at awq.b(SourceFile:1901)
	at awq.e(SourceFile:713)
	at net.minecraft.client.main.Main.main(SourceFile:104)

-- System Details --
Details:
	Minecraft Version: 13w39b
	Operating System: Windows 7 (amd64) version 6.1
	Java Version: 1.7.0_25, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 202411640 bytes (193 MB) / 304545792 bytes (290 MB) up to 954466304 bytes (910 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G
	AABB Pool Size: 10003 (560168 bytes; 0 MB) allocated, 10003 (560168 bytes; 0 MB) used
	IntCache: cache: 1, tcache: 19, allocated: 13, tallocated: 95
	Launched Version: 13w39b
	LWJGL: 2.9.0
	OpenGL: ATI Radeon HD 5700 Series GL version 4.2.12217 Compatibility Profile Context 12.104.0.0, 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 (US)
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 13 (728 bytes; 0 MB) allocated, 13 (728 bytes; 0 MB) used

You can see this full report at http://hopper.minecraft.net/crashes/minecraft/MCX-247438/14586592/