The Parent session seems to be non X11....?

[salan]

Vb Version: Version 6.1.8 r137981 (Qt5.9.5)
Host Mint 19.3 Cinnamon
Latest GA
Guest openSUSE-Leap-15.1 Gnome desktop.
Installed GA with no errors.
When I reboot I get the error.

Screenshot from 2020-06-17 16-33-50.png (21.41 KiB) Viewed 1107 times

Any ideas?
Guest settings are default (2gig ram).
Alan