I have manually installed the fix in comment #7 (thank you, Martin Pitt). I confirm that it now works from the terminal, Synaptic Package Manager, Ubuntu Software Centre, and Settings.
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1026066 Title: software-properties-gtk crashed with ImportError in /usr/lib/python3 /dist-packages/aptdaemon/client.py: No module named gobject To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/aptdaemon/+bug/1026066/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs