I've found that running an Ensemble Optimization,  then opening and closing the polar and then opening the sail chart causes the software to shutdown.  

I recently was switching between two boats. I ran an Optimization for Boat 2 but couldn't remember if I had loaded the correct polar and sail data.  After doing so,  the software shutdown.  I suspected that it was just a general issue with the software and my computer as both were updated in the past month or so.   My IT couldn't find anything amiss. He watched over my shoulder as I just used the software as normal. Then I stumbled on the ensemble/polar/sail sequence and the shutdown repeated.  There was no extreme spike in either CPU or Memory usage immediately before the shutdown.

I have not encountered another sequence that induces the shutdown.   I'll make notes if it happens again.