I use Parallels for online work. I checked the following: influence of second screen on freezes en crashes. First test: connection via miniport adapter to HDMI -> crash with Parallels Technical Report as a result (FINALLY - ID: 347581304). Second test: connection via miniport adapter to VGA -> crash of everything with Apple Crash Report as a result. Of course I have send it in! Conclusion: the only reason for the freezes and crashes are the FaceTime camera. The (type of) connection to a second screen has nothing to do with it. Please solve this problem, Parallels !!!