Steps to reproduce -- very reliable:
Start VM
Suspend VM
Click "sound" (underlined)
get dropdown sheet with message about can't edit suspended VM
Say No (don't want to edit)
Spinning beachball of death
Force quit Parallels.
Restart Parallels
Select original VM from choices, get warning it's already in use
Repeat as often as desired -- it's reliable. One core hovers around 100%
Start VM
Suspend VM
Click "sound" (underlined)
get dropdown sheet with message about can't edit suspended VM
Say No (don't want to edit)
Spinning beachball of death
Force quit Parallels.
Restart Parallels
Select original VM from choices, get warning it's already in use
Repeat as often as desired -- it's reliable. One core hovers around 100%