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-389835/

Crash:

java.lang.NullPointerException: Updating screen events
	at bsl.a(SourceFile:306)
	at bsl.a(SourceFile:112)
	at bsr.a(SourceFile:191)
	at azp.a(SourceFile:793)
	at bcd.c(SourceFile:117)
	at bbw.a(SourceFile:169)
	at bbw.d(SourceFile:236)
	at bbw.k(SourceFile:211)

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

---- Minecraft Crash Report ----
// Ouch. That hurt :(

Time: 10/17/13 2:14 PM
Description: Updating screen events

java.lang.NullPointerException: Updating screen events
	at bsl.a(SourceFile:306)
	at bsl.a(SourceFile:112)
	at bsr.a(SourceFile:191)
	at azp.a(SourceFile:793)
	at bcd.c(SourceFile:117)
	at bbw.a(SourceFile:169)
	at bbw.d(SourceFile:236)
	at bbw.k(SourceFile:211)
	at ayw.o(SourceFile:1296)
	at ayw.ac(SourceFile:749)
	at ayw.e(SourceFile:700)
	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 bsl.a(SourceFile:306)
	at bsl.a(SourceFile:112)
	at bsr.a(SourceFile:191)
	at azp.a(SourceFile:793)
	at bcd.c(SourceFile:117)
	at bbw.a(SourceFile:169)
	at bbw.d(SourceFile:236)
	at bbw.k(SourceFile:211)

-- Affected screen --
Details:
	Screen name: bcc

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [biw['Crafter951'/33, l='MpServer', x=-184.30, y=6.62, z=730.44]]
	Chunk stats: MultiplayerChunkCache: 287, 287
	Level seed: 0
	Level generator: ID 01 - flat, ver 0. Features enabled: false
	Level generator options: 
	Level spawn location: World: (-188,4,653), Chunk: (at 4,0,13 in -12,40; contains blocks -192,0,640 to -177,255,655), Region: (-1,1; contains chunks -32,32 to -1,63, blocks -512,0,512 to -1,255,1023)
	Level time: 1243273 game time, 1220 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: 10 total; [biw['Crafter951'/33, l='MpServer', x=-184.30, y=6.62, z=730.44], wb['entity.MinecartRideable.name'/19, l='MpServer', x=-155.50, y=5.50, z=657.16], wb['entity.MinecartRideable.name'/18, l='MpServer', x=-155.50, y=5.13, z=651.63], up['Chicken'/21, l='MpServer', x=-145.44, y=4.00, z=755.56], up['Chicken'/20, l='MpServer', x=-158.47, y=4.00, z=758.47], wb['entity.MinecartRideable.name'/22, l='MpServer', x=-134.50, y=4.50, z=651.06], uy['Sheep'/12, l='MpServer', x=-241.91, y=4.00, z=736.19], up['Chicken'/28, l='MpServer', x=-123.34, y=4.00, z=733.59], ux['Pig'/14, l='MpServer', x=-241.81, y=4.00, z=752.38], uq['Cow'/15, l='MpServer', x=-232.94, y=4.00, z=761.16]]
	Retry entities: 0 total; []
	Server brand: vanilla
	Server type: Integrated singleplayer server
Stacktrace:
	at bir.a(SourceFile:284)
	at ayw.b(SourceFile:1928)
	at ayw.e(SourceFile:709)
	at net.minecraft.client.main.Main.main(SourceFile:103)

-- System Details --
Details:
	Minecraft Version: 13w42a
	Operating System: Windows 7 (amd64) version 6.1
	Java Version: 1.7.0_25, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 36685416 bytes (34 MB) / 286261248 bytes (273 MB) up to 954466304 bytes (910 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G
	AABB Pool Size: 766 (42896 bytes; 0 MB) allocated, 2 (112 bytes; 0 MB) used
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Launched Version: 13w42a
	LWJGL: 2.9.0
	OpenGL: Intel(R) HD Graphics Family GL version 3.0.0 - Build 8.15.10.2353, Intel
	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: 39 (2184 bytes; 0 MB) allocated, 15 (840 bytes; 0 MB) used
	Anisotropic Filtering: Off (1)

You can see this full report at http://hopper.minecraft.net/crashes/minecraft/MCX-389835/18838737/