Hopper: java.lang.NullPointerException

java.lang.NullPointerException
	at vq.e(SourceFile:271)
	at vq.a(SourceFile:418)
	at azx.g(SourceFile:114)
	at azx.a(SourceFile:158)
	at vo.b(SourceFile:83)
	at vo.a(SourceFile:377)
	at vq.a(SourceFile:120)
	at vr.e(SourceFile:37)
	at nj.a(SourceFile:68)
	at wu.c(SourceFile:78)
	at vo.a(SourceFile:157)
	at bfh.a(SourceFile:295)
	at azw.a(SourceFile:582)
	at azw.b(SourceFile:547)
	at ayw.d(SourceFile:143)
	at ayw.m(SourceFile:110)

---- Minecraft Crash Report ----
// My bad.

Time: 2013-09-07 11:28
Description: Updating screen events

java.lang.NullPointerException
	at vq.e(SourceFile:271)
	at vq.a(SourceFile:418)
	at azx.g(SourceFile:114)
	at azx.a(SourceFile:158)
	at vo.b(SourceFile:83)
	at vo.a(SourceFile:377)
	at vq.a(SourceFile:120)
	at vr.e(SourceFile:37)
	at nj.a(SourceFile:68)
	at wu.c(SourceFile:78)
	at vo.a(SourceFile:157)
	at bfh.a(SourceFile:295)
	at azw.a(SourceFile:582)
	at azw.b(SourceFile:547)
	at ayw.d(SourceFile:143)
	at ayw.m(SourceFile:110)
	at awb.m(SourceFile:1202)
	at awb.V(SourceFile:686)
	at awb.e(SourceFile:642)
	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 vq.e(SourceFile:271)
	at vq.a(SourceFile:418)
	at azx.g(SourceFile:114)
	at azx.a(SourceFile:158)
	at vo.b(SourceFile:83)
	at vo.a(SourceFile:377)
	at vq.a(SourceFile:120)
	at vr.e(SourceFile:37)
	at nj.a(SourceFile:68)
	at wu.c(SourceFile:78)
	at vo.a(SourceFile:157)
	at bfh.a(SourceFile:295)
	at azw.a(SourceFile:582)
	at azw.b(SourceFile:547)
	at ayw.d(SourceFile:143)
	at ayw.m(SourceFile:110)

-- Affected screen --
Details:
	Screen name: azx

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [bfn['MrKeveCool'/23, l='MpServer', x=189,69, y=64,62, z=52,75]]
	Chunk stats: MultiplayerChunkCache: 240, 240
	Level seed: 0
	Level generator: ID 00 - default, ver 1. Features enabled: false
	Level generator options: 
	Level spawn location: World: (256,64,16), Chunk: (at 0,4,0 in 16,1; contains blocks 256,0,16 to 271,255,31), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Level time: 45217 game time, 13817 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: 19 total; [sd['Bat'/51487, l='MpServer', x=244,17, y=18,42, z=101,70], sd['Bat'/50625, l='MpServer', x=150,53, y=24,05, z=83,00], sd['Bat'/50624, l='MpServer', x=147,25, y=23,00, z=84,75], sd['Bat'/51489, l='MpServer', x=270,59, y=40,07, z=-8,95], sd['Bat'/43987, l='MpServer', x=226,38, y=14,10, z=-9,44], sd['Bat'/49440, l='MpServer', x=238,47, y=26,10, z=5,25], sd['Bat'/49441, l='MpServer', x=238,98, y=24,00, z=6,36], sr['Squid'/37427, l='MpServer', x=143,03, y=58,34, z=95,63], sr['Squid'/37425, l='MpServer', x=146,69, y=56,31, z=92,84], sr['Squid'/37727, l='MpServer', x=205,72, y=45,28, z=-10,44], sd['Bat'/24456, l='MpServer', x=221,78, y=31,00, z=77,75], sr['Squid'/37717, l='MpServer', x=209,78, y=50,66, z=-2,50], bfn['MrKeveCool'/23, l='MpServer', x=189,69, y=64,62, z=52,75], sr['Squid'/37224, l='MpServer', x=145,41, y=47,72, z=28,22], sr['Squid'/37227, l='MpServer', x=135,53, y=49,38, z=28,50], sr['Squid'/37222, l='MpServer', x=162,72, y=58,34, z=32,91], sd['Bat'/50623, l='MpServer', x=158,56, y=27,00, z=96,94], sr['Squid'/37328, l='MpServer', x=206,38, y=49,35, z=50,11], sd['Bat'/43917, l='MpServer', x=266,25, y=24,00, z=94,75]]
	Retry entities: 0 total; []
	Server brand: vanilla
	Server type: Integrated singleplayer server
Stacktrace:
	at bfi.a(SourceFile:285)
	at awb.b(SourceFile:1813)
	at awb.e(SourceFile:651)
	at net.minecraft.client.main.Main.main(SourceFile:103)

-- System Details --
Details:
	Minecraft Version: 13w36b
	Operating System: Mac OS X (x86_64) version 10.8.4
	Java Version: 1.6.0_45, Apple Inc.
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Apple Inc.
	Memory: 29150600 bytes (27 MB) / 139567104 bytes (133 MB) up to 1065025536 bytes (1015 MB)
	JVM Flags: 1 total; -Xmx1G
	AABB Pool Size: 1533 (85848 bytes; 0 MB) allocated, 2 (112 bytes; 0 MB) used
	IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 95
	Launched Version: 13w36b
	LWJGL: 2.9.0
	OpenGL: Intel HD Graphics 4000 OpenGL Engine GL version 2.1 INTEL-8.12.47, Intel 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: 4130 (231280 bytes; 0 MB) allocated, 16 (896 bytes; 0 MB) used