src/Tools/jEdit/src/find_dockable.scala

         val snapshot = doc_view.model.snapshot()
         snapshot.node.command_at(doc_view.text_area.getCaretPosition).map(_._1) match {
           case Some(command) =>
             current_location = Some(command)
             current_query = query
-            doc_view.model.add_overlay(command, FIND_THEOREMS, List(instance, query))
+            doc_view.model.insert_overlay(command, FIND_THEOREMS, List(instance, query))
           case None =>
         }
       case None =>
     }