SOLVED: The server didn't send back a proper XML response (2

  if (!function_exists('ob_list_handlers')) {
    @ob_end_clean();
    header("Content-Encoding: none");
  }
  else if ($handlers = sizeof(ob_list_handlers())) {
    while ($handlers--) {
      @ob_end_clean();
    }
    header("Content-Encoding: none");
  }

ob_end_clean() ;