After removing all extensions I can at least log in to a Xorg session. But you get logged into the Activities Overview as expected. Clicking on the desktop then triggers the "Oh no!" (which is gnome-session-failed?).
So it seems the issue is something to do with the vanilla GNOME desktop. We only see the bug sooner when Ubuntu Dock is loaded because that starts on the desktop.
After removing all extensions I can at least log in to a Xorg session. But you get logged into the Activities Overview as expected. Clicking on the desktop then triggers the "Oh no!" (which is gnome-session- failed? ).
So it seems the issue is something to do with the vanilla GNOME desktop. We only see the bug sooner when Ubuntu Dock is loaded because that starts on the desktop.