bug#23260: (wxmaxima) crash: GLib-GIO-ERROR **: Settings schema 'org.gtk.Settings.FileChooser' is not installed

[Danny Milosavljevic]

When I start wxmaxima and go to "Save As", it crashes, printing this message 
beforehand:

(wxmaxima:24842): GLib-GIO-ERROR **: Settings schema 
'org.gtk.Settings.FileChooser' is not installed

Trace/breakpoint trap