Experienced this with Ubuntu 16.04 after using my work desktop station as a temporary server with vagrant servers and using gnome-shell as my DE for about a month. Nautilus started to crash with the error:
cannot open display: :0.0 Maximum number of clients reached Restarting gdm3 didn't work either. Killed all users, and run startx as root launched the gnome-shell and nautilus worked, but I could not make gdm3 start as gdm3 user again. ** Changed in: xorg (Ubuntu) Status: Invalid => Confirmed -- You received this bug notification because you are a member of compiz packagers, which is subscribed to compiz in Ubuntu. https://bugs.launchpad.net/bugs/1518411 Title: "Maximum number of clients reached", new in Ubuntu 15.10 To manage notifications about this bug go to: https://bugs.launchpad.net/compiz/+bug/1518411/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~compiz Post to : compiz@lists.launchpad.net Unsubscribe : https://launchpad.net/~compiz More help : https://help.launchpad.net/ListHelp