Gnome fails to start after switching Nvidia drivers on Ubuntu

If you’ve tried to switch to a different Nvidia graphics driver on Ubuntu and suddenly found that X / Gnome will no longer load and all you have is a command line, you can fix it by switching back to the original driver.

jockey-text -l
jockey-text -e xorg:nvidia_current

These commands will show you a list of drivers available, and then activate the standard Nvidia driver.