Index: openacs-4/packages/xowf/tcl/test-item-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/xowf/tcl/test-item-procs.tcl,v
diff -u -r1.7.2.141 -r1.7.2.142
--- openacs-4/packages/xowf/tcl/test-item-procs.tcl	12 Jun 2021 18:00:34 -0000	1.7.2.141
+++ openacs-4/packages/xowf/tcl/test-item-procs.tcl	21 Jun 2021 10:54:34 -0000	1.7.2.142
@@ -3139,20 +3139,23 @@
           modal_message_dialog_register_submit \
           -url [$wf pretty_link -query m=send-participant-message]
 
+      set bulk_notification_HTML ""
+
       if {$state eq "done"} {
         set uc {tcl {[$p state] ne "done"}}
-        set bulk_notification_HTML ""
       } else {
         set uc {tcl {false}}
 
-        #
-        # Provide bulk notification message dialog to send message to all users
-        #
-        set dialog_info [::xowiki::includelet::personal-notification-messages \
-                            modal_message_dialog -to_user_id $user_list]
-        append dialogs [dict get $dialog_info dialog] \n
-        set notification_dialog_button [dict get $dialog_info link]
-        set bulk_notification_HTML "<div class='bulk-personal-notification-message'>$notification_dialog_button #xowiki.Send_message_to# [llength $user_list] #xowf.Participants#</div>"
+        if {[llength $user_list] > 0} {
+          #
+          # Provide bulk notification message dialog to send message to all users
+          #
+          set dialog_info [::xowiki::includelet::personal-notification-messages \
+                              modal_message_dialog -to_user_id $user_list]
+          append dialogs [dict get $dialog_info dialog] \n
+          set notification_dialog_button [dict get $dialog_info link]
+          set bulk_notification_HTML "<div class='bulk-personal-notification-message'>$notification_dialog_button #xowiki.Send_message_to# [llength $user_list] #xowf.Participants#</div>"
+        }
       }
       #
       # Render table widget with extended properties.