Hello,
So if you create a lens with a PRV in the Multidock, then you go switch to that lens but the project doesn't have a MIDI track, Sonar will crash.  
If you did this with screensets, it would just show you an empty Multidock.
 
Thank You

I cant reproduce that. For starters I cant get a PRV in the multidock without a midi track, not sure how you did that. Anyway, I created a lens with a PRV in the multidock, deleted the midi track and switched lenses, no crashes. The PRV still comes up but says 'Multiple Tracks' on it. Not sure if i'm missing something here??

Hey Adam. 
 
Actually I think you may be onto something here. I just did a couple of tests with lenses active and I can emulate the crash you are seeing by attempting to create a new empty project with an active lense that uses an undocked populated multidock (in my case lyric view on a second monitor). Sonar crashes immediately. I have to load a project that contains data for the multidock and  turn off the lense before I can create an empty project.
 
I can't yet pin down the exact cause as other lenses are not problematic, but hopefully others will try and we can isolate the issue. Are you by any chance using 2 monitors,  and is the multidock situated on the second monitor when your lense is loaded?