How to exit DraftSight on Mac without freeze/crash

Hi,

I have Draftsight 2017 SP0 running on OS X El Cap 10.11.6. Every time I exit Draftsight is freezes and I then have to force quit the app. This causes a crash report to run on opening Draftsight again. Anyway, this has happened for every version of Draftsight I've used on the Mac. Any ideas on how to get it to exit cleanly? Thanks.