diff --git a/gtk2_ardour/mixer_ui.cc b/gtk2_ardour/mixer_ui.cc
index fbfd6f07aa..21643a1a2d 100644
--- a/gtk2_ardour/mixer_ui.cc
+++ b/gtk2_ardour/mixer_ui.cc
@@ -1234,14 +1234,14 @@ Mixer_UI::set_session (Session* sess)
 
 	_group_tabs->set_session (sess);
 
+	update_scene_buttons();
+
 	if (!_session) {
 		favorite_plugins_model->clear ();
 		_selection.clear ();
 		return;
 	}
 
-	update_scene_buttons();
-
 	refill_favorite_plugins();
 
 	XMLNode* node = ARDOUR_UI::instance()->mixer_settings();
@@ -4138,7 +4138,11 @@ Mixer_UI::update_scene_buttons ()
 {
 	bool all_unset = true;
 	for (size_t idx = 0; idx < _mixer_scene_buttons.size (); ++idx) {
-		boost::shared_ptr<MixerScene> scn = _session->nth_mixer_scene (idx);
+		boost::shared_ptr<MixerScene> scn;
+
+		if (_session) {
+			scn = _session->nth_mixer_scene (idx);
+		}
 
 		Gtk::Label* l = _mixer_scene_labels[idx];
 		l->set_alignment (0, 0.5);
@@ -4153,6 +4157,10 @@ Mixer_UI::update_scene_buttons ()
 		}
 	}
 
+	if (!_session) {
+		return;
+	}
+
 	if (_mixer_scene_buttons.size () > 0 && all_unset) {
 		Gtk::Label* l = _mixer_scene_labels[0];
 		l->set_markup(string_compose ("<i>%1</i>", _("(Right-Click to Store)")));