When i insert this:
gksudo nano /etc/default/grub
it replies with this:
(gksudo:(4 digit number, always different)): Gtk-Warning **:cannot onpen display:
But if i type
sudo nano /etc/default/grub it opens the requested file in nano editor.
I've tried to use synaptic package manager to reinstall some stuff, but even after reboot it didn't solve the problem.
Purged the package
gksu and reinstalled, problem still exists.
Searched some stuff but nothing appears about a desktop. I'm using a very very old one, with Lubuntu 14.04.03 32bit LTS. This happened after i changed
nomodeset in GRUB, but i've already removed that and the problem still affects me.