You mounted your virtual machine to Finder using Parallels Mounter. Then you ejected your virtual machine from Finder using the 'eject' button.
Your virtual machine goes to the black screen upon start with the error 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 restart the virtual machine.
Parallels Mounter did not release the virtual machine hard disk, even though it has been ejected from Finder
- Go to Finder and make sure virtual machine disks have been ejected from Finder. If they are still mounted - eject them.
- Go to Finder -> Applications -> Utilities and start Activity Monitor.
Make sure Parallels Mounter and Parallels Explorer are not listed there. If they are running, force quit the process:
- If the issue still persists restart your Mac.