(gecko:16766): GLib-GObject-WARNING **: invalid unclassed pointer in cast to `GtkObject'

(gecko:16766): GLib-GObject-WARNING **: instance with invalid (NULL) class pointer

(gecko:16766): GLib-GObject-CRITICAL **: g_signal_handler_disconnect: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed

(gecko:16766): GLib-GObject-WARNING **: instance with invalid (NULL) class pointer

(gecko:16766): GLib-GObject-CRITICAL **: g_signal_handler_disconnect: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed