public static Object xmlToObject(Element element, Class c, org.apache.logging.log4j.Logger log) {
    try {
        if (log != null) {
            log.debug(element);
            log.debug("este es el resultado ");
        }
        JDOMSource source = new JDOMSource(element);
        JAXBContext context = JAXBContext.newInstance(c);
        Unmarshaller un = context.createUnmarshaller();
        return un.unmarshal(source);
    } catch (JAXBException ex) {
        java.util.logging.Logger.getLogger(SiodexClient.class.getName()).log(Level.SEVERE, null, ex);
    }
    return null;
}

[Exception [EclipseLink-25008] (Eclipse Persistence Services - 2.6.5.v20170607-b3d05bd): org.eclipse.persistence.exceptions.XMLMarshalException
Exception Description: A descriptor with default root element cod_tipo_operacion was not found in the project]
    at org.eclipse.persistence.jaxb.JAXBUnmarshaller.handleXMLMarshalException(JAXBUnmarshaller.java:1110)
    at org.eclipse.persistence.jaxb.JAXBUnmarshaller.unmarshal(JAXBUnmarshaller.java:335)
    at mefp.itg.clws.bcb.siodex.SiodexClient.xmlToObject(SiodexClient.java:216)
    at mefp.itg.clws.bcb.spt.SptClient.consumoServicio(SptClient.java:188)
    at mefp.itg.clws.bcb.spt.SptClient.respuestaEnvio(SptClient.java:74)
    at pag.model.pagosElectronicos.ws.bl.EnvioLotesPagoBL.consumirSWLotes(EnvioLotesPagoBL.java:255)
    at pag.model.pagosElectronicos.ws.bl.EnvioLotesPagoBL.procesarEnvio(EnvioLotesPagoBL.java:38)
    at pag.model.pagosElectronicos.services.AppModulePagosElectronicosImpl.enviarPagos(AppModulePagosElectronicosImpl.java:204)
    at sun.reflect.NativeMethodAccessorImpl