I had the same problem, my file-system went corrupt and when i tried to repair the system packages by shell (safe mode), the same error happened.
I solved this problem with these comands: sudo rm /usr/share/perl5/Debconf/FrontEnd/Gnome.pm sudo aptitude reinstall debconf then it shows you an ask box and choice dialog. system de packages are working great now. i hope this helps -- package xserver-xorg 1:7.3+10ubuntu7 failed to install/upgrade because gnome debconf can not connect to the DISPLAY https://bugs.launchpad.net/bugs/205096 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs