I do not know whether or not this is a bug, although it looks like one! 
Here is what you need to do to correct the situation...
Okay you have the VM's OS set to "Hyper-V (unsupported)" and you need to, at lest temporarily, reset this to Windows 8 x64 (with the VM shutdown, not suspended) and then uncheck the Mirrored Folders check boxes and delete any Shared Folders and turn off Shared Folders. Next boot the VM so it can rectify the changes and then you can again shutdown, not suspend, the VM and reset the setting how you'd like.