Hopper: java.lang.NullPointerException

This is an automatically generated report based from the following crash: http://hopper.minecraft.net/crashes/minecraft/MCX-147353/

Crash:

java.lang.NullPointerException
	at afj.a(SourceFile:927)

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

---- Minecraft Crash Report ----
// There are four lights!

Time: 9/13/13 7:52 PM
Description: Getting biome

java.lang.NullPointerException
	at afj.a(SourceFile:927)
	at add.a(SourceFile:101)
	at adt.a(SourceFile:166)
	at arg.c(SourceFile:73)
	at bio.p(SourceFile:3783)
	at bio.b(SourceFile:122)
	at bhw.a(SourceFile:158)
	at bih.a(SourceFile:1132)
	at bia.a(SourceFile:817)
	at bia.b(SourceFile:697)
	at awo.V(SourceFile:717)
	at awo.e(SourceFile:646)
	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 afj.a(SourceFile:927)

-- Coordinates of biome request --
Details:
	Location: World: (-433,0,-226), Chunk: (at 15,0,14 in -28,-15; contains blocks -448,0,-240 to -433,255,-225), Region: (-1,-1; contains chunks -32,-32 to -1,-1, blocks -512,0,-512 to -1,255,-1)
Stacktrace:
	at add.a(SourceFile:101)
	at adt.a(SourceFile:166)
	at arg.c(SourceFile:73)
	at bio.p(SourceFile:3783)
	at bio.b(SourceFile:122)
	at bhw.a(SourceFile:158)
	at bih.a(SourceFile:1132)
	at bia.a(SourceFile:817)

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [bfz['crittercrust'/12729, l='MpServer', x=-417.00, y=39.15, z=-227.93]]
	Chunk stats: MultiplayerChunkCache: 5, 5
	Level seed: 0
	Level generator: ID 00 - default, ver 1. Features enabled: false
	Level generator options: 
	Level spawn location: World: (156,64,244), Chunk: (at 12,4,4 in 9,15; contains blocks 144,0,240 to 159,255,255), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Level time: 1932 game time, 1932 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: 2 total; [bfz['crittercrust'/12729, l='MpServer', x=-417.00, y=39.15, z=-227.93], uw['Zombie'/12829, l='MpServer', x=-441.50, y=45.00, z=-215.50]]
	Retry entities: 0 total; []
	Server brand: vanilla
	Server type: Integrated singleplayer server
Stacktrace:
	at bfu.a(SourceFile:285)
	at awo.b(SourceFile:1821)
	at awo.e(SourceFile:655)
	at net.minecraft.client.main.Main.main(SourceFile:103)

-- System Details --
Details:
	Minecraft Version: 13w37b
	Operating System: Windows XP (x86) version 5.1
	Java Version: 1.7.0_25, Oracle Corporation
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
	Memory: 231116208 bytes (220 MB) / 571785216 bytes (545 MB) up to 1037959168 bytes (989 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G
	AABB Pool Size: 7955 (445480 bytes; 0 MB) allocated, 15 (840 bytes; 0 MB) used
	IntCache: cache: 0, tcache: 0, allocated: 12, tallocated: 94
	Launched Version: 13w37b
	LWJGL: 2.9.0
	OpenGL: GeForce 8400 GS/PCIe/SSE2 GL version 3.3.0, NVIDIA Corporation
	Is Modded: Probably not. Jar signature remains and client brand is untouched.
	Type: Client (map_client.txt)
	Resource Packs: []
	Current Language: English (US)
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 141 (7896 bytes; 0 MB) allocated, 120 (6720 bytes; 0 MB) used

You can see this full report at http://hopper.minecraft.net/crashes/minecraft/MCX-147353/10646258/