Error while starting gnome-control-center

I get the following error when I try to start gnome-control-center on Kubuntu 19.04: $ gnome-control-center (gnome-control-center:3239): Gtk-WARNING **: 16:12:56.364: Theme parsing error: gtk.css:68:35: The style property GtkButton:child-displacement-x is deprecated and shouldn’t be used anymore. It will be removed in a future version (gnome-control-center:3239): Gtk-WARNING **: 16:12:56.364: Theme parsing error: gtk.css:69:35: The style property GtkButton:child-displacement-y…

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