Weird, I don't see how this could happen.
Anyway it should be easy to fix it: sudo rm /usr/lib/xorg/protocol*.txt sudo apt-get install --reinstall xserver-common
Weird, I don't see how this could happen.
Anyway it should be easy to fix it: xorg/protocol* .txt
sudo rm /usr/lib/
sudo apt-get install --reinstall xserver-common