After upgrading to Windows 10 I faced an ‘unrecoverable error’ when attempting to resume my virtual machines. I found articles recommending you remove the cdrom device as it is handled differently in windows 10 which also led me to notice I could not edit the virtual machine.
Solution – Power down the VM. You will get a warning that the current state of the VM will be lost. Once it is stopped you can then start it again and the unrecoverable error should be gone.