How to fix unable to launch

Question

I get the error when I try to start ubuntu

unable to launch "gnome--session --session=ubuntu" 
X session --- "gnome-session --session=ubuntu" not found; 
falling back to defualt session.

Solution

Error because your desktop session has been messed up. You can recover by reinstalling.

Open virtual console by ctrl+alt+f1 and execute below it will work.

# sudo apt-get install --reinstall ubuntu-desktop
# sudo reboot

Comments

[abo7mid]

in recovery menu I can't move up and down its write read-only

[A.B.]

@abo7mid mount -o remount,rw /

[A.B.]

Why reboot? sudo service lightdm restart