I open a terminal and enter “sudo gedit”, then enter my password and I get:
no protocol specified
Unable to init server: Could not connect: Connection refused
Any idea what is wrong? A workaround would be any other command that would allow me to edit admin-only files.
By default you can’t run a graphic server as root, you can edit the file by terminal with nano, vim, emacs… or let root user run windows with something like this xhost +SI:localuser:root you should do this every system restart, I usually try to use the first option, is safest and fastest.
PS: nano is the easiest editor, to save the file press ctrl+o and enter, to exit crtl+x.
nano is simple. That allowed me to edit an apparmor config file. Thank you very much.
hi there! 
it works for me on ubuntu mate, both with gedit and pluma (gedit fork). mayb u can try to start the filemanager with sudo (nautilus, or the mate fork is caja). or u can try gksudo, however theres a new alternative for gksudo, called polkit. btw what about trying to start it without sudo from terminal, or copy ur user settings to root’s home folder, or delete/rename the existing ones from there? mayb duckduckgo can give u the right answer by the error message… btw caja have a feature, that u can right click in a file browser window, and there u can find something like as open as administrator (try it on a file, and on an empty space as well…) mayb this is an extension that is available for nautilus as well… mayb u can try to reinstall it, or in final case, purge and reinstall… (dont forget about backups, and if u have everything in a safe place, then ur free to experimenting around…)
i think these can be more than enough to find any solution, so good luck, and have fun!