I'm also getting this bug on Ubuntu MATE 20.04 LTS with the exact same error message
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1807529 Title: Attempting to add any widget causes the app to crash. It doesn't seem to matter if I drag the widget or use the keyboard (I'm an orca screen reader user). To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/glade/+bug/1807529/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs