You have gtk 3.19 from a ppa, seems like the issue is that the function signature changed in that update ... the bug doesn't impact Ubuntu proper yet but is going to once gtk is updated, meanwhile that's an Ubuntu GNOME issue
You have gtk 3.19 from a ppa, seems like the issue is that the function signature changed in that update ... the bug doesn't impact Ubuntu proper yet but is going to once gtk is updated, meanwhile that's an Ubuntu GNOME issue