(xfce4-session:1045): xfce4-session-WARNING **: 23:53:22.986: xfsm_manager_load_session: Something wrong with /home/rui/.cache/sessions/xfce4-session-rui-VirtualBox:0, Does it exist? Permissions issue?
(xfwm4:1329): xfwm4-WARNING **: 23:53:23.887: Unsupported GL renderer (llvmpipe (LLVM 9.0.1, 256 bits)).
(wrapper-2.0:1359): GLib-GIO-CRITICAL **: 23:53:26.937: g_file_new_for_path: assertion 'path != NULL' failed
(wrapper-2.0:1359): GLib-GIO-CRITICAL **: 23:53:26.937: g_file_monitor_file: assertion 'G_IS_FILE (file)' failed
(wrapper-2.0:1359): GLib-GObject-WARNING **: 23:53:26.937: invalid (NULL) pointer instance
(wrapper-2.0:1359): GLib-GObject-CRITICAL **: 23:53:26.937: g_signal_connect_data: assertion 'G_TYPE_CHECK_INSTANCE (instance)' failed
(wrapper-2.0:1359): Gtk-WARNING **: 23:53:26.937: Attempting to add a widget with type GtkToggleButton to a container of type XfcePanelPlugin, but the widget is already inside a container of type XfcePanelPlugin, please remove the widget from its existing container first.
(wrapper-2.0:1359): Gtk-WARNING **: 23:53:27.381: Negative content width -3 (allocation 1, extents 2x2) while allocating gadget (node button, owner GtkToggleButton)
(wrapper-2.0:1357): Gtk-WARNING **: 23:53:27.437: Negative content width -3 (allocation 1, extents 2x2) while allocating gadget (node button, owner GtkToggleButton)
(wrapper-2.0:1363): Gtk-WARNING **: 23:53:27.503: Negative content width -3 (allocation 1, extents 2x2) while allocating gadget (node button, owner PulseaudioButton)
(wrapper-2.0:1362): Gtk-WARNING **: 23:53:27.859: Negative content width -3 (allocation 1, extents 2x2) while allocating gadget (node button, owner PowerManagerButton)
(polkit-gnome-authentication-agent-1:1458): GLib-CRITICAL **: 23:53:29.743: g_variant_new_string: assertion 'string != NULL' failed
(polkit-gnome-authentication-agent-1:1458): polkit-gnome-1-WARNING **: 23:53:29.758: Failed to register client: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.gnome.SessionManager was not provided by any .service files
(nm-applet:1425): Gtk-WARNING **: 23:53:31.422: Can't set a parent on widget which has a parent
(xfdesktop:1406): GLib-CRITICAL **: 23:54:05.746: g_variant_new_string: assertion 'string != NULL' failed