Use Atmosphere of Special Effects Vol.2 Natural Phenomenon, apply Colorful Sky 01.iAtm and then deleting the Sky causes iClone to crash
STEPS TO REPRODUCE 1. Install Content Pack: Special Effects Vol.2 Natural Phenomenon 2. Launch iClone 6, navigate to Content Manager > Set > Props > Special Effects Vol.2 Natural Phenomenon 3. Apply a random Props content 4. Apply a random Atmosphere content 5. Go to Scene Manager, delete the applied props/atmosphere content