After installing updates on my OpenSuse Leap 15 distribution I suddenly wasn't
able to enter into a graphical login screen after rebooting my HP computer with
an Intel(R) HD Graphics 630 videocard. 

I discussed the matter on the OpenSuse forums, here's a link:
https://forums.opensuse.org/showthread.php/534276-Open-Suse-suddenly-won-t-boot-on-a-dual-boot-PC/page2

After examining a journalctl file it became clear that the gdm displaymanager
was failing to start under a Wayland session. Here's a paste bin link with the
logfile:
https://pastebin.com/0ngcnYwH
Look for lines 1512 - 1517 where the error occurs.

My OpenSuse distribution is now running under X11 with the lightdm
displaymanager. This way I am able to enter into a graphical environment but
not under Wayland with gdm.