From Fedora Project Wiki
Broken Gnome 3?
This bug has raised its head for a number of users: primarily those using the nVidia binary drivers, in whatever form.
If you have this bug, you will see:
Unable to initialize clutter unable to find suitable fbconfig for the GLX context
... in your user's ~/.xsession-errors file.
Fix It
Step 1.
You need to run, as root:
yum downgrade gnome-shell xulrunner firefox
If you don't have firefox installed, then you wouldn't need that package listed in the command.
Step 2.
As the xulrunner update is a security update, you will also need to ensure it doesn't automatically get reapplied the next reboot.
There are two ways of doing this:
- going to your software update settings, and turning off "Automatically apply security updates"
- adding 'exclude=gnome-shell firefox xulrunner' to your /etc/yum.conf
You really want either of these changes to be temporary, so on the assumption that fixed packages will be created and mirrored out you might want to set your alarm clock for the 1st July and revert this change then.