Gnome 3 crashing (or really gdm not starting?)

On my work laptop running Fedora 22 I suddenly had this problem where (I thought) gnome 3 was crashing. I ended up working around it either by: 1) a) changing the kernel line in grub2 to boot into single-user mode b) changing the target to multi-user.target c) logging in as my user d) starting gnome 3 with 'startx' 2) a) change the default target to multi-user.target b) reboot c) login as my user on the console d) startx There were no errors in Xorg.0.log. After a week of this and fruitlessly looking through journalctl output, I realized that: a) gnome 3 probably wasn't crashing, since: i) I could start it from startx ii) I wasn't even getting the chance to login to begin with b) it was probably a problem getting gdm started I searched on google for something like '"fedora 22" gdm crash blinking screen' and found this: https://www.maketecheasier.com/fix-wayland-gdm-issue-fedora/ And edited custom.conf and uncommented the 'WaylandEnable=false' line and rebooted. That was it. Phew. I could have done a much more efficient job of debugging this, but I kept forgetting about the problem in the first place, since I was so busy at work, once I got the desktop up, I'd completely forget about the original issue until I came in again the next morning.