crash

---- Minecraft Crash Report ----
// Uh... Did I do that?

Time: 6/30/13 4:32 PM
Description: Rendering screen

java.lang.IllegalArgumentException: Modifier name cannot be empty
	at org.apache.commons.lang3.Validate.notEmpty(Validate.java:398)
	at oq.<init>(SourceFile:31)
	at tm.a(SourceFile:94)
	at xz.D(SourceFile:580)
	at xz.a(SourceFile:471)
	at awp.a(SourceFile:188)
	at awp.a(SourceFile:168)
	at bet.b(SourceFile:718)
	at atn.S(SourceFile:685)
	at atn.d(SourceFile:618)
	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 org.apache.commons.lang3.Validate.notEmpty(Validate.java:398)
	at oq.<init>(SourceFile:31)
	at tm.a(SourceFile:94)
	at xz.D(SourceFile:580)
	at xz.a(SourceFile:471)
	at awp.a(SourceFile:188)
	at awp.a(SourceFile:168)

-- Screen render details --
Details:
	Screen name: axa
	Mouse location: Scaled: (338, 154). Absolute: (677, 437)
	Screen size: Scaled: (683, 373). Absolute: (1366, 746). Scale factor of 2

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [bcx['KyuubisSlave'/1, l='MpServer', x=-223.76, y=57.62, z=-2718.93]]
	Chunk stats: MultiplayerChunkCache: 441
	Level seed: 0
	Level generator: ID 01 - flat, ver 0. Features enabled: false
	Level generator options: 
	Level spawn location: World: (-248,4,-2715), Chunk: (at 8,0,5 in -16,-170; contains blocks -256,0,-2720 to -241,255,-2705), Region: (-1,-6; contains chunks -32,-192 to -1,-161, blocks -512,0,-3072 to -1,255,-2561)
	Level time: 19087 game time, 3457 day time
	Level dimension: 0
	Level storage version: 0x00000 - Unknown?
	Level weather: Rain time: 0 (now: false), thunder time: 0 (now: false)
	Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: false
	Forced entities: 1 total; [bcx['KyuubisSlave'/1, l='MpServer', x=-223.76, y=57.62, z=-2718.93]]
	Retry entities: 0 total; []
Stacktrace:
	at bcu.a(SourceFile:284)
	at atn.b(SourceFile:1743)
	at atn.d(SourceFile:627)
	at net.minecraft.client.main.Main.main(SourceFile:101)

-- System Details --
Details:
	Minecraft Version: 1.6.1
	Operating System: Windows 7 (amd64) version 6.1
	Java Version: 1.7.0_13, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 33485488 bytes (31 MB) / 282120192 bytes (269 MB) up to 1037959168 bytes (989 MB)
	JVM Flags: 1 total; -Xmx1G
	AABB Pool Size: 9254 (518224 bytes; 0 MB) allocated, 5 (280 bytes; 0 MB) used
	Suspicious classes: No suspicious classes found.
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Launched Version: 1.6.1
	LWJGL: 2.9.0
	OpenGL: GeForce 6150SE nForce 430/integrated/SSE2 GL version 2.1.2, NVIDIA Corporation
	Is Modded: Probably not. Jar signature remains and client brand is untouched.
	Type: Client (map_client.txt)
	Resource Pack: Default
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 199 (11144 bytes; 0 MB) allocated, 37 (2072 bytes; 0 MB) used