I'm having the same crashing problems since the update. It's happening on both my studio DAW and my portable laptop DAW that i use for remote recording so it's got to be something in the update. I tried rolling back to October and that didn't work so I reinstalled the most recent update. I tried it again and it didn't work...but, for some reason I started up Sonar again (without rebooting the computer) and tried to open the same project and it worked. This also is consistent with the laptop DAW.
In summary, on both my laptop DAW and studio DAW, Sonar doesn't crash when it opens. It crashes when it tries to open a project. Like I mentioned above, if I start up Sonar again after the crash and try to open the same project it works. I have never had problems with Cakewalk programs or Sonar so this is unusual and I'm not happy that I have to go through this to get the program running but at least I'm not dead in the water....at the moment