My minecraft keeps crashing

I don't know what happens. I cannot connect to servers or single player games. When I try, my minecraft client crashes. Here is the crash report from my last crash:

---- Minecraft Crash Report ----
// Don't be sad. I'll do better next time, I promise!

Time: 11/28/12 5:20 PM
Description: Unexpected error

java.lang.NoClassDefFoundError: com/pclewis/mcpatcher/mod/RenderPassAPI
	at bac.a(SourceFile:857)
	at bac.b(SourceFile:751)
	at net.minecraft.client.Minecraft.J(SourceFile:604)
	at net.minecraft.client.Minecraft.run(SourceFile:534)
	at java.lang.Thread.run(Thread.java:680)
Caused by: java.lang.ClassNotFoundException: com.pclewis.mcpatcher.mod.RenderPassAPI
	at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
	... 5 more


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

-- Head --
Stacktrace:
	at bac.a(SourceFile:857)

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [ayk['boogeyboard123'/59, l='MpServer', x=-37.47, y=290.22, z=-26.12]]
	Chunk stats: MultiplayerChunkCache: 25
	Level seed: 0
	Level generator: ID 01 - flat, ver 0. Features enabled: false
	Level generator options: 
	Level spawn location: World: (0,4,0), Chunk: (at 0,0,0 in 0,0; contains blocks 0,0,0 to 15,255,15), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Level time: 88181 game time, 39408 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: 44 total; [pd['Pig'/4, l='MpServer', x=-65.06, y=237.00, z=-51.97], pd['Pig'/5, l='MpServer', x=-74.13, y=237.00, z=-39.25], pd['Pig'/6, l='MpServer', x=-70.94, y=237.00, z=-40.03], pd['Pig'/7, l='MpServer', x=-69.03, y=237.00, z=-43.94], pd['Pig'/8, l='MpServer', x=-77.63, y=237.00, z=-25.13], pd['Pig'/9, l='MpServer', x=-76.88, y=237.00, z=-9.72], pd['Pig'/10, l='MpServer', x=-65.59, y=237.00, z=7.25], pd['Pig'/12, l='MpServer', x=-57.78, y=237.00, z=-50.19], ayk['boogeyboard123'/59, l='MpServer', x=-37.47, y=290.22, z=-26.12], pd['Pig'/13, l='MpServer', x=-55.75, y=237.00, z=-32.22], pd['Pig'/14, l='MpServer', x=-50.06, y=237.00, z=-41.03], pd['Pig'/15, l='MpServer', x=-58.81, y=237.00, z=-23.50], pd['Pig'/17, l='MpServer', x=-60.75, y=237.00, z=-17.16], pd['Pig'/16, l='MpServer', x=-60.38, y=237.00, z=-23.81], pe['Sheep'/19, l='MpServer', x=-61.69, y=237.00, z=14.84], pd['Pig'/18, l='MpServer', x=-60.16, y=237.00, z=-14.81], pd['Pig'/20, l='MpServer', x=-62.09, y=237.00, z=3.91], pd['Pig'/23, l='MpServer', x=-33.97, y=237.00, z=-61.09], pd['Pig'/25, l='MpServer', x=-41.56, y=237.00, z=-63.72], pd['Pig'/24, l='MpServer', x=-33.63, y=237.00, z=-55.75], pd['Pig'/27, l='MpServer', x=-44.34, y=237.00, z=-50.81], pd['Pig'/26, l='MpServer', x=-42.06, y=237.00, z=-52.78], pd['Pig'/29, l='MpServer', x=-41.91, y=237.00, z=-39.91], pd['Pig'/28, l='MpServer', x=-44.06, y=237.00, z=-55.19], pd['Pig'/31, l='MpServer', x=-39.50, y=237.31, z=-35.56], py['Minecart'/30, l='MpServer', x=-39.50, y=238.41, z=-35.59], pd['Pig'/34, l='MpServer', x=-39.16, y=237.00, z=-31.19], pd['Pig'/35, l='MpServer', x=-38.16, y=237.00, z=-20.84], pd['Pig'/32, l='MpServer', x=-40.22, y=237.00, z=-27.75], pd['Pig'/33, l='MpServer', x=-41.53, y=237.00, z=-26.66], pd['Pig'/38, l='MpServer', x=-42.22, y=237.00, z=-25.53], pd['Pig'/39, l='MpServer', x=-44.25, y=237.00, z=-29.13], pd['Pig'/36, l='MpServer', x=-35.28, y=237.00, z=-25.13], pd['Pig'/37, l='MpServer', x=-40.50, y=237.00, z=-24.47], pd['Pig'/42, l='MpServer', x=-20.22, y=237.00, z=-57.66], pd['Pig'/43, l='MpServer', x=-19.84, y=237.00, z=-52.91], pd['Pig'/40, l='MpServer', x=-36.94, y=237.00, z=-26.94], pd['Pig'/46, l='MpServer', x=-22.19, y=237.00, z=-7.50], pd['Pig'/47, l='MpServer', x=-20.97, y=237.00, z=-7.06], pd['Pig'/44, l='MpServer', x=-29.03, y=237.00, z=-47.16], pd['Pig'/45, l='MpServer', x=-31.13, y=237.00, z=-20.22], pd['Pig'/50, l='MpServer', x=-8.16, y=237.00, z=-18.53], pe['Sheep'/49, l='MpServer', x=-31.16, y=237.00, z=14.88], pd['Pig'/48, l='MpServer', x=-27.03, y=237.00, z=-12.94]]
	Retry entities: 0 total; []
Stacktrace:
	at ayh.a(SourceFile:290)
	at net.minecraft.client.Minecraft.b(SourceFile:1870)
	at net.minecraft.client.Minecraft.run(SourceFile:548)
	at java.lang.Thread.run(Thread.java:680)

-- System Details --
Details:
	Minecraft Version: 1.4.5
	Operating System: Mac OS X (x86_64) version 10.7.5
	Java Version: 1.6.0_37, Apple Inc.
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Apple Inc.
	Memory: 307858496 bytes (293 MB) / 581435392 bytes (554 MB) up to 1065025536 bytes (1015 MB)
	JVM Flags: 3 total; -Xbootclasspath/a:/System/Library/PrivateFrameworks/JavaApplicationLauncher.framework/Resources/LauncherSupport.jar -Xms512M -Xmx1024M
	AABB Pool Size: 10819 (605864 bytes; 0 MB) allocated, 10819 (605864 bytes; 0 MB) used
	Suspicious classes: [com.pclewis.mcpatcher.MCPatcherUtils, Config, ChangeHandler, ...], [com.pclewis.mcpatcher.mod.TileSize, TextureUtils, FontUtils, ...]
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	LWJGL: 2.4.2
	OpenGL: Intel HD Graphics 4000 OpenGL Engine GL version 2.1 APPLE-7.32.12, Intel Inc.
	Is Modded: Very likely; Jar signature invalidated
	Type: Client (map_client.txt)
	Texture Pack: Sphax PureBDCraft 128x MC14
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 25 (1400 bytes; 0 MB) allocated, 25 (1400 bytes; 0 MB) used