--- loncom/interface/courseprefs.pm	2014/06/13 01:48:26	1.67
+++ loncom/interface/courseprefs.pm	2014/08/03 01:47:49	1.68
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # Handler to set configuration settings for a course
 #
-# $Id: courseprefs.pm,v 1.67 2014/06/13 01:48:26 raeburn Exp $
+# $Id: courseprefs.pm,v 1.68 2014/08/03 01:47:49 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -2624,9 +2624,9 @@ sub display_loncaparev_constraints {
         }
         foreach my $map (keys(%allmaps)) {
             my $mapres = $navmap->getResourceByUrl($map);
-            my $mapsymb = $mapres->symb();
-            $toshow{$mapsymb} = 1;
             if (ref($mapres)) {
+                my $mapsymb = $mapres->symb();
+                $toshow{$mapsymb} = 1;
                 my $pcslist = $mapres->map_hierarchy();
                 if ($pcslist ne '') {
                     foreach my $pc (split(/,/,$pcslist)) {