I had a different problem with the app hanging, so I uninstalled it and put it on another Mac, copying over my VM from 3.0. This time it would launch, but in upgrading the VM to 4.0 it would error out on step 2 after spending about 20 minutes looking for devices. The VM is basically dead as it won't boot, but fortunately I did make a copy of it. PD 4.0 is DOA for me, unworkable on two Macs, one a laptop and the other a Mac Pro. I'm curious at the percentage of people who have no problems with the upgrade.