Hopper: java.lang.NullPointerException

java.lang.NullPointerException
	at bav.a(SourceFile:200)
	at bam.b(SourceFile:382)
	at bam.a(SourceFile:259)
	at bau.a(SourceFile:122)

---- Minecraft Crash Report ----
// Don't do that.

Time: 10/10/13 17:20
Description: Rendering screen

java.lang.NullPointerException
	at bav.a(SourceFile:200)
	at bam.b(SourceFile:382)
	at bam.a(SourceFile:259)
	at bau.a(SourceFile:122)
	at bkv.b(SourceFile:851)
	at ays.ab(SourceFile:783)
	at ays.e(SourceFile:706)
	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 bav.a(SourceFile:200)
	at bam.b(SourceFile:382)
	at bam.a(SourceFile:259)
	at bau.a(SourceFile:122)

-- Screen render details --
Details:
	Screen name: bau
	Mouse location: Scaled: (152, 223). Absolute: (304, 32)
	Screen size: Scaled: (427, 240). Absolute: (854, 480). Scale factor of 2
Stacktrace:
	at bkv.b(SourceFile:851)
	at ays.ab(SourceFile:783)
	at ays.e(SourceFile:706)
	at net.minecraft.client.main.Main.main(SourceFile:103)

-- System Details --
Details:
	Minecraft Version: 13w41a
	Operating System: Windows 7 (x86) version 6.1
	Java Version: 1.6.0_39, Sun Microsystems Inc.
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode, sharing), Sun Microsystems Inc.
	Memory: 219495952 bytes (209 MB) / 309174272 bytes (294 MB) up to 518979584 bytes (494 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M
	AABB Pool Size: 31630 (1771280 bytes; 1 MB) allocated, 0 (0 bytes; 0 MB) used
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Launched Version: 13w41a
	LWJGL: 2.9.0
	OpenGL: ATI Radeon HD 3200 Graphics   GL version 2.1.8794, 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