I have a serious issue that I don't understand. When I start my computer elementary won't open the graphical window to log in and instead it starts a tty terminal. To get the graphical login window I have to login in the tty and run
sudo /etc/init.d/lightdm stop sudo /etc/init.d/lightdm start
Sometimes it takes a few minutes (about 2min max) before it shows the dock and the menu-bar.
I didn't do anything to have this problem. Just some regular updates...
Update : thanks to @bigbang it's resolved by running this command :
sudo dpkg-reconfigure lightdm