Hopper: java.lang.NullPointerException bct.a(SourceFile:897)

java.lang.NullPointerException
	at bct.a(SourceFile:897)
	at du.a(SourceFile:17)
	at cn.b(SourceFile:354)
	at bct.e(SourceFile:98)
	at bcv.c(SourceFile:71)

---- Minecraft Crash Report ----
// Sorry :(

Time: 8/3/13 10:25 AM
Description: Ticking screen

java.lang.NullPointerException
	at bct.a(SourceFile:897)
	at du.a(SourceFile:17)
	at cn.b(SourceFile:354)
	at bct.e(SourceFile:98)
	at bcv.c(SourceFile:71)
	at ats.k(SourceFile:1173)
	at ats.S(SourceFile:663)
	at ats.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 bct.a(SourceFile:897)
	at du.a(SourceFile:17)
	at cn.b(SourceFile:354)
	at bct.e(SourceFile:98)
	at bcv.c(SourceFile:71)

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

-- System Details --
Details:
	Minecraft Version: 1.6.2
	Operating System: Mac OS X (x86_64) version 10.6.8
	Java Version: 1.6.0_51, Apple Inc.
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Apple Inc.
	Memory: 114086016 bytes (108 MB) / 163962880 bytes (156 MB) up to 1069416448 bytes (1019 MB)
	JVM Flags: 1 total; -Xmx1G
	AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
	Suspicious classes: No suspicious classes found.
	IntCache: cache: 0, tcache: 0, allocated: 3, tallocated: 63
	Launched Version: 1.6.2
	LWJGL: 2.9.0
	OpenGL: NVIDIA GeForce 9400 OpenGL Engine GL version 2.1 NVIDIA-1.6.36, NVIDIA Corporation
	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