src/Tools/jEdit/src/document_model.scala

                 model1.set_node_required(required); (true, st)
               case _ => (false, st)
             }
         })
     if (changed) {
-      PIDE.options_changed()
+      PIDE.plugin.options_changed()
       PIDE.editor.flush()
     }
   }
 
   def view_node_required(view: View, toggle: Boolean = false, set: Boolean = false): Unit =