This is a bit of a drastic solution, but try running the following after quitting Sublime:
mv ~/.config/sublime-text-3/Packages/User ~
rm -rf ~/.config/sublime-text-3
You're going to have to set up all your preferences and plugins again, but backing up the Packages/User
folder will help with that.
If even that doesn't work, you'll have to reinstall Sublime. The best way is to download the appropriate Ubuntu .deb
file, then install it with
sudo dpkg -i sublime-text_buildXXXX.deb
replacing the file name with the one you downloaded.
I'm not sure exactly what is happening, but something is seriously messed up. Make sure that when you run Sublime again for the first time after following the steps above that you do it as your regular user, not using sudo
.
Good luck!