Hopper: java.lang.NullPointerException

java.lang.NullPointerException
	at ayg.a(SourceFile:199)
	at axx.b(SourceFile:374)
	at axx.a(SourceFile:259)
	at ayf.a(SourceFile:122)

---- Minecraft Crash Report ----
// Don't be sad. I'll do better next time, I promise!

Time: 12.09.13 17:00
Description: Rendering screen

java.lang.NullPointerException
	at ayg.a(SourceFile:199)
	at axx.b(SourceFile:374)
	at axx.a(SourceFile:259)
	at ayf.a(SourceFile:122)
	at bhx.b(SourceFile:720)
	at awl.V(SourceFile:717)
	at awl.e(SourceFile:646)
	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 ayg.a(SourceFile:199)
	at axx.b(SourceFile:374)
	at axx.a(SourceFile:259)
	at ayf.a(SourceFile:122)

-- Screen render details --
Details:
	Screen name: ayf
	Mouse location: Scaled: (378, 473). Absolute: (757, 41)
	Screen size: Scaled: (840, 494). Absolute: (1680, 988). Scale factor of 2
Stacktrace:
	at bhx.b(SourceFile:720)
	at awl.V(SourceFile:717)
	at awl.e(SourceFile:646)
	at net.minecraft.client.main.Main.main(SourceFile:103)

-- System Details --
Details:
	Minecraft Version: 13w37a
	Operating System: Windows 7 (x86) version 6.1
	Java Version: 1.7.0_25, Oracle Corporation
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode, sharing), Oracle Corporation
	Memory: 168433536 bytes (160 MB) / 287924224 bytes (274 MB) up to 518979584 bytes (494 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M
	AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
	IntCache: cache: 0, tcache: 0, allocated: 12, tallocated: 94
	Launched Version: 13w37a
	LWJGL: 2.9.0
	OpenGL: GeForce 9400 GT/PCIe/SSE2 GL version 3.3.0, NVIDIA Corporation
	Is Modded: Probably not. Jar signature remains and client brand is untouched.
	Type: Client (map_client.txt)
	Resource Packs: [faithful32pack.zip]
	Current Language: English (US)
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: ~~ERROR~~ NullPointerException: null