Upgrading to Fedora 25 was as easy as clicking a button in Fedora 24 then waiting.
But after the reboot it didn’t come back up as expected. Instead it displayed the image above. I believe this is known as the Gnome Fail Whale.
And this is what fixed it for me:
- See the Gnome Fail Whale
- Press Ctrl-Alt-F2 to drop into single user mode
- Sign in as my normal user
- Edit this file /usr/share/gnome-session/sessions/gnome.session as sudo
- Remove gnome-settings-daemon; from the last line
Not yet sure what the consequences of this are besides frustration.