Type Reason InvalidOperationException No element was open, or the XmlTextWriter.WriteState is WriteState.Closed.
In the dnprdnext release, the recommended practice is to create System.Xml.XmlWriter instances using the erload:System.Xml.XmlWriter.Create method and the System.Xml.XmlWriterSettings class. This allows you to take full advantage of all the new features introduced in this release. For more information, see Creating XML Writers.
If the element contains no content a short end tag "/>" is written; otherwise a full end tag is written.