The ability to boot from my external SSD broke after upgrading from version 19 to 20. I just get a blank screen. To be clear, that is, a Windows 10 installation that resides on the external hard drive that is actually also dual-bootable on my Intel Mac, not a .pvm file on the hard drive.
The setup wasn't modified -- via "boot order", "external device" is selected and the dropdown for the external boot device is set to the exact same drive as before. I also checked /Library/Preferences/Parallels/dispatcher.desktop.xml and both "usb" and "removable drive" are flagged as on.
<UsbVirtualDisks dyn_lists="">
<FireWire>1</FireWire>
<Usb>1</Usb>
<Thunderbolt>1</Thunderbolt>
<Removable>1</Removable>
</UsbVirtualDisks>
