.xsession errors showed repeated:
(Gecko:14304): Gdk-CRITICAL **: gdk_pixbuf_get_from_drawable: assertion `gdk_window_is_viewable (src)' failed
(Gecko:14304): GdkPixbuf-CRITICAL **: gdk_pixbuf_get_n_channels: assertion `pixbuf != NULL' failed
(Gecko:14304): GdkPixbuf-CRITICAL **: gdk_pixbuf_get_bits_per_sample: assertion `pixbuf != NULL' failed
(Gecko:14304): GdkPixbuf-CRITICAL **: gdk_pixbuf_get_width: assertion `pixbuf != NULL' failed
(Gecko:14304): GdkPixbuf-CRITICAL **: gdk_pixbuf_get_height: assertion `pixbuf != NULL' failed
(Gecko:14304): GdkPixbuf-CRITICAL **: gdk_pixbuf_get_rowstride: assertion `pixbuf != NULL' failed
(Gecko:14304): GLib-GObject-CRITICAL **: g_object_unref: assertion `G_IS_OBJECT (object)' failed
(Gecko:14304): Gdk-CRITICAL **: gdk_pixbuf_get_from_drawable: assertion `gdk_window_is_viewable (src)' failed