Crash Cloth?

inecraft Crash Report ----
// Quite honestly, I wouldn't worry myself about that.

Time: 10/17/13 10:09 PM
Description: There was a severe problem during mod loading that has caused the game to fail

cpw.mods.fml.common.LoaderException: java.lang.NoClassDefFoundError: net/minecraft/block/BlockCloth
	at cpw.mods.fml.common.LoadController.transition(LoadController.java:149)
	at cpw.mods.fml.common.Loader.initializeMods(Loader.java:697)
	at cpw.mods.fml.client.FMLClientHandler.finishMinecraftLoading(FMLClientHandler.java:249)
	at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:509)
	at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:808)
	at net.minecraft.client.main.Main.main(SourceFile:101)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:601)
	at net.minecraft.launchwrapper.Launch.launch(Launch.java:131)
	at net.minecraft.launchwrapper.Launch.main(Launch.java:27)
Caused by: java.lang.NoClassDefFoundError: net/minecraft/block/BlockCloth
	at extrautils.ExtraUtils.load(ExtraUtils.java:456)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:601)
	at cpw.mods.fml.common.FMLModContainer.handleModStateEvent(FMLModContainer.java:545)
	at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:601)
	at com.google.common.eventbus.EventHandler.handleEvent(EventHandler.java:74)
	at com.google.common.eventbus.SynchronizedEventHandler.handleEvent(SynchronizedEventHandler.java:45)
	at com.google.common.eventbus.EventBus.dispatch(EventBus.java:313)
	at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:296)
	at com.google.common.eventbus.EventBus.post(EventBus.java:267)
	at cpw.mods.fml.common.LoadController.sendEventToModContainer(LoadController.java:194)
	at cpw.mods.fml.common.LoadController.propogateStateMessage(LoadController.java:174)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:601)
	at com.google.common.eventbus.EventHandler.handleEvent(EventHandler.java:74)
	at com.google.common.eventbus.SynchronizedEventHandler.handleEvent(SynchronizedEventHandler.java:45)
	at com.google.common.eventbus.EventBus.dispatch(EventBus.java:313)
	at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:296)
	at com.google.common.eventbus.EventBus.post(EventBus.java:267)
	at cpw.mods.fml.common.LoadController.distributeStateMessage(LoadController.java:105)
	at cpw.mods.fml.common.Loader.initializeMods(Loader.java:696)
	... 10 more
Caused by: java.lang.ClassNotFoundException: net.minecraft.block.BlockCloth
	at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:186)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:423)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
	... 37 more