Minecraft Forums

So I play this mod pack and i play it daily but i switched my profil to 1.8.1 to play on a server and then went back and i pressed play and it loads and then opens the launcher again and says already playing then i try again a few times and crashes imediatly.

Heres the crash report

---- Minecraft Crash Report ----
// I let you down. Sorry

Time: 3/18/15 9:39 PM
Description: Initializing game

java.lang.NoClassDefFoundError: com/arcanumLudum/ALCore/render/IGuiModule
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:344)
at cpw.mods.fml.common.FMLModContainer.constructMod(FMLModContainer.java:420)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
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 cpw.mods.fml.common.LoadController.sendEventToModContainer(LoadController.java:208)
at cpw.mods.fml.common.LoadController.propogateStateMessage(LoadController.java:187)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
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)