Hopper: java.lang.NullPointerException: Updating screen events

This is an automatically generated report based from the following crash: http://hopper.minecraft.net/crashes/minecraft/MCX-315807/

Crash:

java.lang.NullPointerException: Updating screen events
	at aer.a(SourceFile:36)
	at yv.h(SourceFile:135)
	at yv.a(SourceFile:77)
	at zb.c(SourceFile:77)
	at xv.a(SourceFile:222)
	at bif.a(SourceFile:305)
	at bcp.a(SourceFile:490)
	at bcp.b(SourceFile:463)
	at bbp.d(SourceFile:240)
	at bbp.k(SourceFile:211)

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

---- Minecraft Crash Report ----
// Who set us up the TNT?

Time: 12/10/13 14:51
Description: Updating screen events

java.lang.NullPointerException: Updating screen events
	at aer.a(SourceFile:36)
	at yv.h(SourceFile:135)
	at yv.a(SourceFile:77)
	at zb.c(SourceFile:77)
	at xv.a(SourceFile:222)
	at bif.a(SourceFile:305)
	at bcp.a(SourceFile:490)
	at bcp.b(SourceFile:463)
	at bbp.d(SourceFile:240)
	at bbp.k(SourceFile:211)
	at ayp.o(SourceFile:1303)
	at ayp.ab(SourceFile:755)
	at ayp.e(SourceFile:706)
	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 aer.a(SourceFile:36)
	at yv.h(SourceFile:135)
	at yv.a(SourceFile:77)
	at zb.c(SourceFile:77)
	at xv.a(SourceFile:222)
	at bif.a(SourceFile:305)
	at bcp.a(SourceFile:490)
	at bcp.b(SourceFile:463)
	at bbp.d(SourceFile:240)
	at bbp.k(SourceFile:211)

-- Affected screen --
Details:
	Screen name: bdn

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [bil['JBman100'/74, l='MpServer', x=-98,11, y=57,62, z=209,30]]
	Chunk stats: MultiplayerChunkCache: 270, 270
	Level seed: 0
	Level generator: ID 00 - default, ver 1. Features enabled: false
	Level generator options: 
	Level spawn location: World: (-414,56,209), Chunk: (at 2,3,1 in -26,13; contains blocks -416,0,208 to -401,255,223), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
	Level time: 1640095 game time, 33014 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: survival (ID 0). Hardcore: false. Cheats: false
	Forced entities: 6 total; [bil['JBman100'/74, l='MpServer', x=-98,11, y=57,62, z=209,30], bil['JBman100'/74, l='MpServer', x=-341,39, y=-268,49, z=211,05], wy['Villager'/127871, l='MpServer', x=-96,84, y=56,00, z=206,44], uv['Squid'/154909, l='MpServer', x=-141,50, y=56,00, z=211,50], uh['Bat'/143447, l='MpServer', x=-127,25, y=55,10, z=210,25], uh['Bat'/151345, l='MpServer', x=-127,25, y=55,10, z=210,25]]
	Retry entities: 0 total; []
	Server brand: vanilla
	Server type: Integrated singleplayer server
Stacktrace:
	at big.a(SourceFile:302)
	at ayp.b(SourceFile:1935)
	at ayp.e(SourceFile:715)
	at net.minecraft.client.main.Main.main(SourceFile:103)

-- System Details --
Details:
	Minecraft Version: 13w41b
	Operating System: Mac OS X (x86_64) version 10.8.5
	Java Version: 1.6.0_51, Apple Inc.
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Apple Inc.
	Memory: 82796896 bytes (78 MB) / 186007552 bytes (177 MB) up to 1060372480 bytes (1011 MB)
	JVM Flags: 1 total; -Xmx1G
	AABB Pool Size: 707 (39592 bytes; 0 MB) allocated, 3 (168 bytes; 0 MB) used
	IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 95
	Launched Version: 13w41b
	LWJGL: 2.9.0
	OpenGL: ATI Radeon HD 4850 OpenGL Engine GL version 2.1 ATI-8.16.74, 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 (UK)
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 77 (4312 bytes; 0 MB) allocated, 26 (1456 bytes; 0 MB) used
	Anisotropic Filtering: Off (1)

You can see this full report at http://hopper.minecraft.net/crashes/minecraft/MCX-315807/17181351/