Did you do the latest updates from Crestron and this is an older file? I had very similar issues, with the exact same unexpected error, and TB said sometimes after doing an update Systembuilder thinks it's working with the old database and can screw things up. Open the file, choose archive, then import it back in. You'll have to rename it but who cares. I've started doing this after every Crestron update and 99.9% of my issues have vanished.