Index: openacs-4/packages/forums/tcl/messages-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/forums/tcl/messages-procs.tcl,v
diff -u -r1.46.2.3 -r1.46.2.4
--- openacs-4/packages/forums/tcl/messages-procs.tcl	22 Apr 2017 12:28:32 -0000	1.46.2.3
+++ openacs-4/packages/forums/tcl/messages-procs.tcl	27 Apr 2017 12:12:53 -0000	1.46.2.4
@@ -273,7 +273,7 @@
 	}
 
 	if { [forum::use_ReadingInfo_p] 
-	     && [db_string is_root "select parent_id from forums_messages where message_id = :message_id"] eq ""  
+	     && [db_string is_root "select parent_id from forums_messages where message_id = :message_id" -default ""] eq ""
 	 } {
 	    set db_antwort [db_string forums_reading_info__remove_msg {
 		select forums_reading_info__remove_msg (:message_id);