src/Tools/jEdit/src/jedit/ScrollerDockable.scala

     Isabelle.plugin.font_changed += (font => {
       if (Isabelle.plugin.font != null)
         fontResolver.setFontMapping("Isabelle", Isabelle.plugin.font)
       panel.relayout()
     })
-    val tree = YXML.parse_failsafe(Isabelle.symbols.decode(r.result))
+    val tree = IsabelleProcess.parse_message(r.kind, Isabelle.symbols.decode(r.result))
     val document = XML.document(tree)
     panel.setDocument(document, UserAgent.baseURL)
     val sa = new SelectionActions
     sa.install(panel)
     panel