Caused by: java.lang.NoClassDefFoundError: nc/tile/processor/Processors$TileManufactory at nc.init.NCBlocks.init(NCBlocks.java:151) at nc.proxy.CommonProxy.preInit(CommonProxy.java:54) at nc.proxy.ClientProxy.preInit(ClientProxy.java:30) at nc.NuclearCraft.preInit(NuclearCraft.java:34) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at net.minecraftforge.fml.common.FMLModContainer.handleModStateEvent(FMLModContainer.java:616) at sun.reflect.GeneratedMethodAccessor2.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at com.google.common.eventbus.EventSubscriber.handleEvent(EventSubscriber.java:74) at com.google.common.eventbus.SynchronizedEventSubscriber.handleEvent(SynchronizedEventSubscriber.java:47) at com.google.common.eventbus.EventBus.dispatch(EventBus.java:322) at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:304) at com.google.common.eventbus.EventBus.post(EventBus.java:275) at net.minecraftforge.fml.common.LoadController.sendEventToModContainer(LoadController.java:243) at net.minecraftforge.fml.common.LoadController.propogateStateMessage(LoadController.java:221) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at com.google.common.eventbus.EventSubscriber.handleEvent(EventSubscriber.java:74) at com.google.common.eventbus.SynchronizedEventSubscriber.handleEvent(SynchronizedEventSubscriber.java:47) at com.google.common.eventbus.EventBus.dispatch(EventBus.java:322) at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:304) at com.google.common.eventbus.EventBus.post(EventBus.java:275) at net.minecraftforge.fml.common.LoadController.distributeStateMessage(LoadController.java:145) at net.minecraftforge.fml.common.Loader.preinitializeMods(Loader.java:624) at net.minecraftforge.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:259) at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:439) at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:351) at net.minecraft.client.main.Main.main(SourceFile:124) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at net.minecraft.launchwrapper.Launch.launch(Launch.java:135) at net.minecraft.launchwrapper.Launch.main(Launch.java:28) Caused by: java.lang.ClassNotFoundException: nc.tile.processor.Processors$TileManufactory at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:191) at java.lang.ClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) ... 40 more Caused by: java.lang.NoClassDefFoundError: nc/tile/processor/TileEnergyItemProcessor at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(Unknown Source) at java.security.SecureClassLoader.defineClass(Unknown Source) at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:182) ... 42 more Caused by: java.lang.ClassNotFoundException: nc.tile.processor.TileEnergyItemProcessor at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:101) at java.lang.ClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) ... 46 more

I don't think NC has any coremods.

This might now be fixed in 2.3 - could you confirm if it is, as I can't recreate this issue.