Hopper: java.lang.NullPointerException

java.lang.NullPointerException
	at bcw.a(SourceFile:841)
	at fz.a(SourceFile:46)
	at co.b(SourceFile:354)
	at bcw.e(SourceFile:98)
	at bdk.c(SourceFile:31)

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

Time: 10/13/13 6:19 PM
Description: Ticking screen

java.lang.NullPointerException
	at bcw.a(SourceFile:841)
	at fz.a(SourceFile:46)
	at co.b(SourceFile:354)
	at bcw.e(SourceFile:98)
	at bdk.c(SourceFile:31)
	at atv.k(SourceFile:1173)
	at atv.S(SourceFile:663)
	at atv.d(SourceFile:619)
	at net.minecraft.client.main.Main.main(SourceFile:101)


A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

-- Head --
Stacktrace:
	at bcw.a(SourceFile:841)
	at fz.a(SourceFile:46)
	at co.b(SourceFile:354)
	at bcw.e(SourceFile:98)
	at bdk.c(SourceFile:31)

-- Affected screen --
Details:
	Screen name: bda
Stacktrace:
	at atv.k(SourceFile:1173)
	at atv.S(SourceFile:663)
	at atv.d(SourceFile:619)
	at net.minecraft.client.main.Main.main(SourceFile:101)

-- System Details --
Details:
	Minecraft Version: 1.6.4
	Operating System: Mac OS X (x86_64) version 10.8
	Java Version: 1.6.0_45, Apple Inc.
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Apple Inc.
	Memory: 123811720 bytes (118 MB) / 243601408 bytes (232 MB) up to 1065025536 bytes (1015 MB)
	JVM Flags: 1 total; -Xmx1G
	AABB Pool Size: 30118 (1686608 bytes; 1 MB) allocated, 2 (112 bytes; 0 MB) used
	Suspicious classes: No suspicious classes found.
	IntCache: cache: 0, tcache: 0, allocated: 3, tallocated: 63
	Launched Version: 1.6.4
	LWJGL: 2.9.0
	OpenGL: Intel HD Graphics 4000 OpenGL Engine GL version 2.1 APPLE-8.0.51, Intel Inc.
	Is Modded: Probably not. Jar signature remains and client brand is untouched.
	Type: Client (map_client.txt)
	Resource Pack: Default
	Current Language: English (US)
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: ~~ERROR~~ NullPointerException: null