Check this question, and similar questions first.
It happens when there are two different version of nvidia driver in the system. It is a known issue. You need to take care of the nvidia version of your kernel and the graphic card identical.
Or,
If you didn't uninstall your previous driver version. This can happen because nvidia-current-dev is of version 304 and nvidia-current-updates-dev is of version 319 as reported.
If you've installed the nVidia driver from Ubuntu's Additional Drivers dialogue
, try
sudo apt-get purge nvidia*
then try reinstalling by
sudo apt-get install nvidia-current-updates-dev
then reboot.
If you have used the .run file from nVidia's website then go to a console by pressing Alt+Ctrl+F1 and then run
nvidia-xxx-pkg1.run --uninstall
to remove the previous driver components. Now give a reboot and see if that works. If not, then execute
sudo echo "blacklist nouveau" >> /etc/modprobe.d/blacklist.conf
so that the default nouveau driver for nVidia chipsets are not loaded instead of proprietary one. Finally install packaged binary drivers by
sudo apt-get install nvidia-current-updates-dev
chekc this link as well.