Robert Ancell authored Oct 15, 2018 and Robert Ancell committed Feb 05, 2019

The warning is:
(gnome-control-center:29760): Gtk-CRITICAL **: 11:45:48.076: gtk_widget_is_visible: assertion 'GTK_IS_WIDGET (widget)' failed

This is due to the code trying to disable switches that only exist if support
for that feature is available.