Hopper: java.lang.NullPointerException

java.lang.NullPointerException
	at azf.a(SourceFile:73)
	at bbd.a(SourceFile:159)

---- Minecraft Crash Report ----
// Don't do that.

Time: 12/09/13 17:10
Description: Rendering screen

java.lang.NullPointerException
	at azf.a(SourceFile:73)
	at bbd.a(SourceFile:159)
	at bhx.b(SourceFile:720)
	at awl.V(SourceFile:717)
	at awl.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 azf.a(SourceFile:73)
	at bbd.a(SourceFile:159)

-- Screen render details --
Details:
	Screen name: bbd
	Mouse location: Scaled: (389, 127). Absolute: (779, 450)
	Screen size: Scaled: (683, 353). Absolute: (1366, 706). Scale factor of 2

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [bfw['operationguard'/53630, l='MpServer', x=1000.80, y=65.62, z=-8.14]]
	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: (0,64,0), Chunk: (at 0,4,0 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)
	Level time: 800546 game time, 6000 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: adventure (ID 2). Hardcore: false. Cheats: false
	Forced entities: 16 total; [va['Villager'/53638, l='MpServer', x=1002.50, y=52.00, z=0.50], va['Villager'/53639, l='MpServer', x=1000.50, y=52.00, z=0.50], va['Villager'/53636, l='MpServer', x=1004.50, y=52.00, z=0.50], va['Villager'/53637, l='MpServer', x=1006.50, y=52.00, z=0.50], bfw['operationguard'/53630, l='MpServer', x=1000.80, y=65.62, z=-8.14], va['Villager'/53635, l='MpServer', x=990.50, y=52.00, z=0.50], pa['entity.ItemFrame.name'/53632, l='MpServer', x=1002.50, y=65.50, z=-11.94], pi['Painting'/53631, l='MpServer', x=999.50, y=65.50, z=-11.94], va['Crazy Ed'/53633, l='MpServer', x=1001.00, y=64.00, z=-10.50], pi['Painting'/53631, l='MpServer', x=999.50, y=65.50, z=-11.94], va['Villager'/53644, l='MpServer', x=1010.50, y=52.00, z=0.50], va['Villager'/53645, l='MpServer', x=1008.50, y=52.00, z=0.50], va['Villager'/53642, l='MpServer', x=994.50, y=52.00, z=0.50], va['Villager'/53643, l='MpServer', x=992.50, y=52.00, z=0.50], va['Villager'/53640, l='MpServer', x=998.50, y=52.00, z=0.50], va['Villager'/53641, l='MpServer', x=996.50, y=52.00, z=0.50]]
	Retry entities: 0 total; []
	Server brand: vanilla
	Server type: Integrated singleplayer server
Stacktrace:
	at bfr.a(SourceFile:285)
	at awl.b(SourceFile:1821)
	at awl.e(SourceFile:655)
	at net.minecraft.client.main.Main.main(SourceFile:103)

-- System Details --
Details:
	Minecraft Version: 13w37a
	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: 70560184 bytes (67 MB) / 423202816 bytes (403 MB) up to 518979584 bytes (494 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M
	AABB Pool Size: 156 (8736 bytes; 0 MB) allocated, 156 (8736 bytes; 0 MB) used
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Launched Version: 13w37a
	LWJGL: 2.9.0
	OpenGL: ATI Mobility Radeon HD 4250          GL version 3.2.9712 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 (US)
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 85 (4760 bytes; 0 MB) allocated, 85 (4760 bytes; 0 MB) used