src/Tools/jEdit/src/active.scala

                 }
 
               case XML.Elem(Markup(Markup.SIMP_TRACE_PANEL, props), _) =>
                 val link =
                   props match {
-                    case Position.Id(id) => PIDE.editor.hyperlink_command(true, snapshot, id)
+                    case Position.Id(id) => JEdit_Editor.hyperlink_command(true, snapshot, id)
                     case _ => None
                   }
                 GUI_Thread.later {
                   link.foreach(_.follow(view))
                   view.getDockableWindowManager.showDockableWindow("isabelle-simplifier-trace")