Hopper: java.lang.NullPointerException: Updating screen events

java.lang.NullPointerException: Updating screen events
	at bcc.r_(SourceFile:35)
	at bcd.a(SourceFile:197)
	at azd.a(SourceFile:641)
	at bce.a(SourceFile:131)
	at bcd.a(SourceFile:172)
	at bcd.d(SourceFile:236)
	at bcd.k(SourceFile:211)

---- Minecraft Crash Report ----
// Oh - I know what I did wrong!

Time: 10/26/13 9:55 AM
Description: Updating screen events

java.lang.NullPointerException: Updating screen events
	at bcc.r_(SourceFile:35)
	at bcd.a(SourceFile:197)
	at azd.a(SourceFile:641)
	at bce.a(SourceFile:131)
	at bcd.a(SourceFile:172)
	at bcd.d(SourceFile:236)
	at bcd.k(SourceFile:211)
	at azd.o(SourceFile:1303)
	at azd.ad(SourceFile:753)
	at azd.e(SourceFile:704)
	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 bcc.r_(SourceFile:35)
	at bcd.a(SourceFile:197)
	at azd.a(SourceFile:641)
	at bce.a(SourceFile:131)
	at bcd.a(SourceFile:172)
	at bcd.d(SourceFile:236)
	at bcd.k(SourceFile:211)

-- Affected screen --
Details:
	Screen name: bcc
Stacktrace:
	at azd.o(SourceFile:1303)
	at azd.ad(SourceFile:753)
	at azd.e(SourceFile:704)
	at net.minecraft.client.main.Main.main(SourceFile:103)

-- System Details --
Details:
	Minecraft Version: 1.7.2
	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: 208452960 bytes (198 MB) / 330088448 bytes (314 MB) up to 1065025536 bytes (1015 MB)
	JVM Flags: 1 total; -Xmx1G
	AABB Pool Size: 4021 (225176 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
	IntCache: cache: 0, tcache: 0, allocated: 12, tallocated: 94
	Launched Version: 1.7.2
	LWJGL: 2.9.1
	OpenGL: NVIDIA GeForce GT 330M OpenGL Engine GL version 2.1 NVIDIA-1.6.40, NVIDIA Corporation
	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
	Anisotropic Filtering: Off (1)