Hopper: java.lang.NullPointerException

java.lang.NullPointerException
	at azi.a(SourceFile:73)
	at bbg.a(SourceFile:159)

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

Time: 13-9-13 15:04
Description: Rendering screen

java.lang.NullPointerException
	at azi.a(SourceFile:73)
	at bbg.a(SourceFile:159)
	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:159)

-- Screen render details --
Details:
	Screen name: bbg
	Mouse location: Scaled: (388, 130). Absolute: (777, 456)
	Screen size: Scaled: (680, 359). Absolute: (1360, 718). Scale factor of 2

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [bfz['EastCap96'/102, l='MpServer', x=-385,33, y=65,62, z=424,13]]
	Chunk stats: MultiplayerChunkCache: 314, 314
	Level seed: 0
	Level generator: ID 00 - default, ver 1. Features enabled: false
	Level generator options: 
	Level spawn location: World: (-236,64,256), Chunk: (at 4,4,0 in -15,16; contains blocks -240,0,256 to -225,255,271), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
	Level time: 1073663 game time, 341598 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: 22 total; [pj['Painting'/0, l='MpServer', x=-422,94, y=72,50, z=403,00], pj['Painting'/1, l='MpServer', x=-422,94, y=71,50, z=404,50], pj['Painting'/2, l='MpServer', x=-422,94, y=71,50, z=402,50], pj['Painting'/74, l='MpServer', x=-191,06, y=66,50, z=388,00], vb['Villager'/3, l='MpServer', x=-421,69, y=70,00, z=405,06], pj['Painting'/73, l='MpServer', x=-191,06, y=66,00, z=390,50], pj['Painting'/56, l='MpServer', x=-196,94, y=156,00, z=394,50], pj['Painting'/57, l='MpServer', x=-193,06, y=156,00, z=395,50], vb['Villager'/9, l='MpServer', x=-387,50, y=64,00, z=423,72], vb['Villager'/11, l='MpServer', x=-375,78, y=64,00, z=428,50], vb['Villager'/12, l='MpServer', x=-369,59, y=64,00, z=416,31], pj['Painting'/72, l='MpServer', x=-191,06, y=66,50, z=393,00], pj['Painting'/71, l='MpServer', x=-187,00, y=65,50, z=391,94], vb['Villager'/25074, l='MpServer', x=-395,31, y=64,00, z=425,84], vb['Villager'/25072, l='MpServer', x=-392,50, y=65,00, z=385,50], vb['Villager'/25073, l='MpServer', x=-384,31, y=64,00, z=413,84], pj['Painting'/0, l='MpServer', x=-422,94, y=72,50, z=403,00], pj['Painting'/1, l='MpServer', x=-422,94, y=71,50, z=404,50], pj['Painting'/2, l='MpServer', x=-422,94, y=71,50, z=402,50], vb['Villager'/25267, l='MpServer', x=-401,84, y=69,00, z=395,66], vb['Villager'/25268, l='MpServer', x=-400,38, y=70,00, z=409,78], bfz['EastCap96'/102, l='MpServer', x=-385,33, y=65,62, z=424,13]]
	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 Vista (x86) version 6.0
	Java Version: 1.7.0_25, Oracle Corporation
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode, sharing), Oracle Corporation
	Memory: 83477080 bytes (79 MB) / 229531648 bytes (218 MB) up to 518979584 bytes (494 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M
	AABB Pool Size: 15868 (888608 bytes; 0 MB) allocated, 326 (18256 bytes; 0 MB) used
	IntCache: cache: 0, tcache: 0, allocated: 12, tallocated: 94
	Launched Version: 13w37b
	LWJGL: 2.9.0
	OpenGL: GeForce GT 220/PCI/SSE2 GL version 3.0.0, NVIDIA Corporation
	Is Modded: Probably not. Jar signature remains and client brand is untouched.
	Type: Client (map_client.txt)
	Resource Packs: [Feathersong_2.zip]
	Current Language: English (UK)
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 522 (29232 bytes; 0 MB) allocated, 68 (3808 bytes; 0 MB) used