DraftSight 2015 ran fine on my machine under Mac OS X 10.9 "Mavericks".  Since upgrading the operating system to 10.10 "Yosemite", I can't get the application to open.  It appears to start OK, opens a blank drawing editor window, and then crashes, with nothing but a "spinning wheel" cursor, requiring a forced quit.

Has anyone else experienced the same problem?  Anybody have a good work-around?