--- loncom/interface/lonprintout.pm	2017/01/30 19:47:54	1.627.2.20
+++ loncom/interface/lonprintout.pm	2017/05/30 01:30:04	1.627.2.21
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # Printout
 #
-# $Id: lonprintout.pm,v 1.627.2.20 2017/01/30 19:47:54 raeburn Exp $
+# $Id: lonprintout.pm,v 1.627.2.21 2017/05/30 01:30:04 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -3458,7 +3458,9 @@ ENDPART
         if ($env{'request.enc'}) {
             $url = &Apache::lonenc::encrypted($url);
         }
-        $URLback = $url.($url =~ /\?/) ? '&':'?'.'symb='.$helper->{VARS}{'symb'};
+        if ($url ne '') {
+            $URLback = $url.(($url =~ /\?/) ? '&':'?').'symb='.$helper->{VARS}{'symb'};
+        }
     }
     #
     # Final adjustment of the font size: