Sometimes it happens, software crash!  These are issues we occasionally need to work through, particularly with new equipment or software rollouts.  There is no exception for Primescan.  This video is about one of those incidents.  I really had to go after due diligence to save the case.  Fortunately, when I do a CEREC workflow with multiple units or that is unique, I have a habit of saving the case (Save AS) before starting the software design flow.  Having more than one file for a case can save the day!