Hopper: java.lang.NullPointerException

java.lang.NullPointerException
	at ayw.b(SourceFile:179)
	at ayw.C_(SourceFile:175)
	at ayc.a(SourceFile:49)

---- Minecraft Crash Report ----
// Why did you do that?

Time: 9/6/13 11:44 PM
Description: Rendering screen

java.lang.NullPointerException
	at ayw.b(SourceFile:179)
	at ayw.C_(SourceFile:175)
	at ayc.a(SourceFile:49)
	at bho.b(SourceFile:720)
	at awb.V(SourceFile:713)
	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 ayw.b(SourceFile:179)
	at ayw.C_(SourceFile:175)
	at ayc.a(SourceFile:49)

-- Screen render details --
Details:
	Screen name: ayc
	Mouse location: Scaled: (77, 167). Absolute: (154, 145)
	Screen size: Scaled: (427, 240). Absolute: (854, 480). Scale factor of 2
Stacktrace:
	at bho.b(SourceFile:720)
	at awb.V(SourceFile:713)
	at awb.e(SourceFile:642)
	at net.minecraft.client.main.Main.main(SourceFile:103)

-- System Details --
Details:
	Minecraft Version: 13w36b
	Operating System: Windows 7 (amd64) version 6.1
	Java Version: 1.7.0_03, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 206975480 bytes (197 MB) / 338362368 bytes (322 MB) up to 954466304 bytes (910 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G
	AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
	IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 95
	Launched Version: 13w36b
	LWJGL: 2.9.0
	OpenGL: ATI Radeon HD 5900 Series GL version 4.2.12002 Compatibility Profile Context 9.12.0.0, 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: ~~ERROR~~ NullPointerException: null