Hopper: java.lang.NullPointerException

java.lang.NullPointerException
	at azi.a(SourceFile:73)
	at bbg.a(SourceFile:155)

---- Minecraft Crash Report ----
// I bet Cylons wouldn't have this problem.

Time: 9/13/13 1:23 PM
Description: Rendering screen

java.lang.NullPointerException
	at azi.a(SourceFile:73)
	at bbg.a(SourceFile:155)
	at bia.b(SourceFile:720)
	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 azi.a(SourceFile:73)
	at bbg.a(SourceFile:155)

-- Screen render details --
Details:
	Screen name: bbg
	Mouse location: Scaled: (305, 129). Absolute: (610, 450)
	Screen size: Scaled: (683, 355). Absolute: (1366, 709). Scale factor of 2

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [bfz['TheGreenDoctor'/0, l='MpServer', x=-8.36, y=83.62, z=13.51]]
	Chunk stats: MultiplayerChunkCache: 225, 225
	Level seed: 0
	Level generator: ID 01 - flat, ver 0. Features enabled: false
	Level generator options: 
	Level spawn location: World: (-1508,4,597), Chunk: (at 12,0,5 in -95,37; contains blocks -1520,0,592 to -1505,255,607), Region: (-3,1; contains chunks -96,32 to -65,63, blocks -1536,0,512 to -1025,255,1023)
	Level time: 161585 game time, 25401 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; [vb['Villager'/1, l='MpServer', x=-6.50, y=82.00, z=13.50], bfz['TheGreenDoctor'/0, l='MpServer', x=-8.36, y=83.62, z=13.51]]
	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 7 (amd64) version 6.1
	Java Version: 1.7.0_13, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 100941784 bytes (96 MB) / 367001600 bytes (350 MB) up to 954466304 bytes (910 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G
	AABB Pool Size: 7983 (447048 bytes; 0 MB) allocated, 29 (1624 bytes; 0 MB) used
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Launched Version: 13w37b
	LWJGL: 2.9.0
	OpenGL: AMD Radeon HD 6320 Graphics GL version 4.2.12002 Compatibility Profile Context 9.12.0.0, 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: 380 (21280 bytes; 0 MB) allocated, 71 (3976 bytes; 0 MB) used