I'm trying to install Fedora 19. After my computer booted from installation DVD for about 20 minutes, it displays white screen with 'Oh no! Something has gone wrong.' message. I've tried 3 times and it still persists.
Never mind this answer. It's not applicable to the actual situation the OP finds himself in.
Might be this bug from the Fedora 15/16 upgrade returning in the Fedora 18/19 upgrade:
That bug suggests it's a problem with the gnome-settings-daemon crashing on startup due to mismatched color profiles (which apparently changed between releases, but were not updated properly via the updater). Changing to a different console,as terdon suggested:
and then logging into the console will allow you to run the suggested command:
to fix the color profile.
Another thread: http://forums.fedoraforum.org/showthread.php?t=272232 suggests it's a problem with come incomplete updates during the upgrade. Switching to another console as above and logging will allow you to look see if that's the case.
You could also switch to KDE at least temporarily as the bug and forum thread both point to GNOME as the source of the problem.
From the console install KDE and kdm:
then switch to kdm (default is gdm which will work with KDE as well, but you probably need to skip anything gnome related for now (https://fedoraproject.org/wiki/KDE):