DISPLAY=:0 ccsm

sudo apt-get install dconf-tools
dconf reset -f /org/compiz/

sudo apt-get update && apt-get install --reinstall unity ubuntu-desktop lighdm

unity

Error : plugin "opengl" could not be loaded

sudo mv /etc/X11/xorg.conf.XXXXXXXX /usr/share/X11/xorg.conf.d/xorg.conf

export DISPLAY=:0

gsettings reset org.compiz.core:/org/compiz/profiles/unity/plugins/core/ active-plugins