I was using Korg Wavestation VST.  Programing drums in the piano roll view.  Added another instance of Wavestation while drums were playing and Sonar crashed.  Never had this happen before.  It has happened twice since most recent update.  Reported it to the Bakers but any assistance is welcomed.

Add the second instance of Wavestation with Sonar stopped.  Does it still crash?
 
I always stop the transport before adding an instance of a synth.  Best practice.
 
Update:  Just tried it and Sonar doesn't crash here even while the transport is running.  I did have to get reissue codes for everything though...that shows you how long it's been since I used these...they are great synths - Wavestation, M1, Legacy Cell, MonoPoly, MS-20, and Polysix...all load on this computer...which is my Studio B and not the one listed in my sig...