Hopper: java.lang.NoClassDefFoundError: paulscode/sound/codecs/CodecJOrbis

java.lang.NoClassDefFoundError: paulscode/sound/codecs/CodecJOrbis
	at bnz.<init>(SourceFile:56)
	at awb.Q(SourceFile:331)

---- Minecraft Crash Report ----
// Who set us up the TNT?

Time: 6/09/13 21:41
Description: Initializing game

java.lang.NoClassDefFoundError: paulscode/sound/codecs/CodecJOrbis
	at bnz.<init>(SourceFile:56)
	at awb.Q(SourceFile:331)
	at awb.e(SourceFile:622)
	at net.minecraft.client.main.Main.main(SourceFile:103)
Caused by: java.lang.ClassNotFoundException: paulscode.sound.codecs.CodecJOrbis
	at java.net.URLClassLoader$1.run(Unknown Source)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(Unknown Source)
	at java.lang.ClassLoader.loadClass(Unknown Source)
	at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
	at java.lang.ClassLoader.loadClass(Unknown Source)
	... 4 more


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

-- Head --
Stacktrace:
	at bnz.<init>(SourceFile:56)
	at awb.Q(SourceFile:331)

-- Initialization --
Details:
Stacktrace:
	at awb.e(SourceFile:622)
	at net.minecraft.client.main.Main.main(SourceFile:103)

-- System Details --
Details:
	Minecraft Version: 13w36b
	Operating System: Windows 7 (x86) version 6.1
	Java Version: 1.6.0_20, Sun Microsystems Inc.
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode, sharing), Sun Microsystems Inc.
	Memory: 7862640 bytes (7 MB) / 26808320 bytes (25 MB) up to 518979584 bytes (494 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M
	AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Launched Version: 13w36b
	LWJGL: 2.9.0
	OpenGL: GeForce GT 525M/PCI/SSE2 GL version 4.1.0, NVIDIA Corporation
	Is Modded: Probably not. Jar signature remains and client brand is untouched.
	Type: Client (map_client.txt)
	Resource Packs: []
	Current Language: Español (España)
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: ~~ERROR~~ NullPointerException: null