Hopper: java.lang.NullPointerException

This is an automatically generated report based from the following crash: http://hopper.minecraft.net/crashes/minecraft/MCX-76234/

Crash:

java.lang.NullPointerException
	at ny.f(SourceFile:108)
	at zj.n(SourceFile:184)
	at yx.s(SourceFile:363)
	at yx.a(SourceFile:406)
	at azr.a(SourceFile:188)
	at baf.a(SourceFile:581)
	at azr.a(SourceFile:168)
	at bai.a(SourceFile:30)
	at baf.a(SourceFile:530)

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

---- Minecraft Crash Report ----
// I'm sorry, Dave.

Time: 9/5/13 4:28 PM
Description: Rendering screen

java.lang.NullPointerException
	at ny.f(SourceFile:108)
	at zj.n(SourceFile:184)
	at yx.s(SourceFile:363)
	at yx.a(SourceFile:406)
	at azr.a(SourceFile:188)
	at baf.a(SourceFile:581)
	at azr.a(SourceFile:168)
	at bai.a(SourceFile:30)
	at baf.a(SourceFile:530)
	at bhh.b(SourceFile:720)
	at avx.V(SourceFile:713)
	at avx.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 ny.f(SourceFile:108)
	at zj.n(SourceFile:184)
	at yx.s(SourceFile:363)
	at yx.a(SourceFile:406)
	at azr.a(SourceFile:188)
	at baf.a(SourceFile:581)
	at azr.a(SourceFile:168)
	at bai.a(SourceFile:30)
	at baf.a(SourceFile:530)

-- Screen render details --
Details:
	Screen name: baf
	Mouse location: Scaled: (159, 170). Absolute: (318, 139)
	Screen size: Scaled: (427, 240). Absolute: (854, 480). Scale factor of 2

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [bfg['SilentZoom'/4, l='MpServer', x=-845.79, y=53.62, z=-109.50]]
	Chunk stats: MultiplayerChunkCache: 190, 190
	Level seed: 0
	Level generator: ID 01 - flat, ver 0. Features enabled: false
	Level generator options: 
	Level spawn location: World: (-853,4,-109), Chunk: (at 11,0,3 in -54,-7; contains blocks -864,0,-112 to -849,255,-97), Region: (-2,-1; contains chunks -64,-32 to -33,-1, blocks -1024,0,-512 to -513,255,-1)
	Level time: 9694 game time, 9694 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: 5 total; [tj['item.item.porkchopRaw'/0, l='MpServer', x=-853.66, y=50.13, z=-97.75], tj['item.tile.button'/1, l='MpServer', x=-853.38, y=50.13, z=-96.28], tj['item.tile.button'/2, l='MpServer', x=-851.22, y=52.13, z=-98.66], tj['item.tile.sandStone.default'/3, l='MpServer', x=-856.50, y=52.13, z=-101.25], bfg['SilentZoom'/4, l='MpServer', x=-845.79, y=53.62, z=-109.50]]
	Retry entities: 0 total; []
	Server brand: vanilla
	Server type: Integrated singleplayer server
Stacktrace:
	at bfb.a(SourceFile:285)
	at avx.b(SourceFile:1813)
	at avx.e(SourceFile:651)
	at net.minecraft.client.main.Main.main(SourceFile:103)

-- System Details --
Details:
	Minecraft Version: 13w36a
	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: 240746488 bytes (229 MB) / 494731264 bytes (471 MB) up to 954466304 bytes (910 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G
	AABB Pool Size: 933 (52248 bytes; 0 MB) allocated, 5 (280 bytes; 0 MB) used
	Suspicious classes: [com.ibm.icu.text.ArabicShapingException], [gnu.trove.TIntCollection], [gnu.trove.impl.HashFunctions, PrimeFinder], [gnu.trove.impl.hash.THash, TPrimitiveHash, TIntIntHash], [gnu.trove.iterator.TIterator, TAdvancingIterator, TIntIntIterator], [gnu.trove.map.TIntIntMap], [gnu.trove.map.hash.TIntIntHashMap], [gnu.trove.procedure.TIntIntProcedure], [gnu.trove.set.TIntSet]
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Launched Version: 13w36a
	LWJGL: 2.9.0
	OpenGL: ATI Radeon HD 4200  GL version 3.3.9836 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: 255 (14280 bytes; 0 MB) allocated, 27 (1512 bytes; 0 MB) used

You can see this full report at http://hopper.minecraft.net/crashes/minecraft/MCX-76234/8215325/