So I am using the kamino mushplatform_interior, but when I clean and munge it, or just munge it, when I play, I just fall through the floor. What is up with this and fow do I fix it?

thanks

Just looking at the models with 3D unwrap, while the interior does have some collisions the mushplatform1 has most of the floor collisions. So choices are add mushplatform1 to your map if possible, or use invisible columns under the floor or take the interior into xsi to create proper collisions (or just make a floor collision in xsi that will suit you needs.