castor unmarshaling exceptin

Хочу создать коллекцию объектов на основе xml:

получаю такую ошибку.

org.xml.sax.SAXException: unable to find FieldDescriptor for 'Settings' in ClassDescriptor of com.castor.test.Ui-settings-dTO
at org.exolab.castor.xml.UnmarshalHandler.startElement(UnmarshalHandler.java:815)
at org.apache.xerces.parsers.SAXParser.startElement(SAXParser.java:1340)
at org.apache.xerces.validators.common.XMLValidator.callStartElement(XMLValidator.java:1284)
at org.apache.xerces.framework.XMLDocumentScanner$ContentDispatcher.dispatch(XMLDocumentScanner.java:1171)
at org.apache.xerces.framework.XMLDocumentScanner.parseSome(XMLDocumentScanner.java:381)
at org.apache.xerces.framework.XMLParser.parse(XMLParser.java:1098)
at org.exolab.castor.xml.Unmarshaller.unmarshal(Unmarshaller.java:338)
at org.exolab.castor.xml.Unmarshaller.unmarshal(Unmarshaller.java:270)
at com.castor.test.XmlLogic.readUIConstants(XmlLogic.java:37)
at com.castor.test.Main.main(Main.java:35)


java 1.4
castor 0.9.3.9

что значит эта ошибка??