Errors when closing app
After closing the app, without doing any prior action, one gets
(app-icon-preview:2): Gtk-CRITICAL **: 23:47:26.555: gtk_widget_get_state_flags: assertion 'GTK_IS_WIDGET (widget)' failed
(app-icon-preview:2): Gtk-CRITICAL **: 23:47:26.555: gtk_widget_has_css_class: assertion 'GTK_IS_WIDGET (widget)' failed