src/Pure/Thy/document_build.scala

         val selected = document_selection(name.theory)
 
         val body =
           if (selected) {
             val entry = session_context(name.theory, Export.DOCUMENT_LATEX, permissive = true)
-            YXML.parse_body(entry.text)
+            YXML.parse_body(entry.bytes)
           }
           else {
             val text =
               proper_string(session_context.theory_source(name.theory)) getOrElse
                 File.read(name.path)