A Fault occurs on the server side while executing the webservice request from my client. The server side code is not under my control, its under the control of Microsoft. They give back a soap message containing a fault like it is defined in the wsdl contract. Example: 2009-05-27 21:40:22,329 TRACE [org.jboss.ws.core.MessageTrace#traceMessage] Incoming Response Message | <s:Envelope xmlns:s='http://schemas.xmlsoap.org/soap/envelope/'> | <s:Body> | <s:Fault xmlns:s='http://schemas.xmlsoap.org/soap/envelope/'> | <faultcode>s:Client</faultcode> | <faultstring xml:lang='en-US'>Request Failed. See the Exception Log for details.</faultstring> | <detail> | <AifFault xmlns='http://schemas.microsoft.com/dynamics/2008/01/documents/Fault&... xmlns:i='http://www.w3.org/2001/XMLSchema-instance'> | <CustomDetailXml i:nil='true'/> | <FaultMessageListArray i:nil='true'/> | </AifFault> | </detail> | </s:Fault> | </s:Body> | </s:Envelope> | JBossWS was not able to read or unmarshal such a message into the corresponding objects. I downloaded the the code and added "implements Serializable" to SOAPFaultImpl and a few others and now the communication between JBossWS-Client and the MS software based on WCF (Windows Communication Foundation) on the server side. I wonder that nobody had the problem before and that the released versions of JBossWS are not capable of reading answers like the one above. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4233737#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...