I have posted several times because all builds since 1970 were unable to find my existing .pvs files. When I started Parallels, instead of a list of VMs I just got the OS Installer assistant. I have found the cause of this problem and fixed it. For reasons I no longer remember, long ago I had renamed the standard Documents folder of my main user ID, and had created an alias called Documents that pointed to the actual folder. This works fine for nearly all software, and used to work for Parallels up to Release 1970. I tried deleting the Documents alias and renaming my main doc folder back to Documents. I also followed some instructions in another thread about setting up a hidden folder of aliases to the .pvs files. I don't know if both steps were needed, but Parallels now starts up with a list of my virtual machines, and I can configure or start any of them.