I hope someone can help. I am now on day two of this nightmare, and I need to get my virtual machine up and running so I can do my job. I'm running MacOS High Sierra 10.13.6. Two days ago, I upgraded my Parallels installation, and now my Windows 10 virtual machine won't load. I receive the following message: Unable to connect Hard Disk 1. A file or device required for the operation of Hard Disk 1 does not exists or is used by another process, or you have no permission to access it. The virtual machine will continue running, but the device will be disconnected. When I click OK, I receive the following message: There is no operating system installed in this virtual machine. To install an OS, connect a source with OS installation files, such as a CD, thumb drive, or disk image, and reset the virtual machine. For more information, see Parallels Desktop Help. When I click OK, I see a screen that reads: Parallels Virtual Platform 15.0.0 (46967) Continue Select Language Boot Manager Device Manager Boot Maintenance Manager I have reached out to the Parallels support team, both by email and telephone. The tech who answered my email immediately closed my support ticket after providing the following instructions: Please restart your Mac without checking "open apps after restarting the mac" option and try starting Parallels Desktop and Windows virtual machine. If the issue still persists, please refer to the below KB article steps: https://kb.parallels.com/124280 Clicking on the above link results in a "permission denied" message. I called the support team and spoke to a tech who had me set and reset file permissions, which also did not solve my problem. Eventually, I was told my issue was going to be referred to their "concerned team." That was yesterday, and I haven't heard anything from them since. I've tried the following on my own: Restoring Time Machine backups of my .pvm file. When I try to load them, I get a message that says a file is missing or in use, and then I receive the same messages as above. Uninstalling Parallels 15 and reverting to version 14. Same problems. Creating a new Windows 10 virtual machine and tried to attach to the .HDD file, which fails. Using Parallels Mounter to attach to the .HDD file, which also fails. I've resorted to recovery efforts using a utility called BitRecover -- it has been running all night, and still isn't finished with its analysis. Help!