So basically i downloaded mo creatures and the mob spawner, everything worked fine for the past 3 weeks and all of the sudden my minecraft crashed and everytime i want to go back in a world it crashes. If i remove the custom mob spawner out of the mods folder it works fine but my creatures are gone and if i put it back in it crashes again. Does anyone know how to fix this or what is going on. It's version 1.7.2. by the way but it's still weird. if someone know how i can fix this problem please tell me thanks.