I've developed an WebService with JAXB2 and XFire. I've managed to get the web service to run successfully on Tomcat - both by using a Java client and a .net client. When deploying the war file to the resin server I get an exception on the client, I've reconfigured the resin server according to the wiki page: http://docs.codehaus.org/display/XFIRE/Resin By adding the following configuration: <system-property javax.xml.parsers.DocumentBuilderFactory="org.apache.xerces.jaxp.DocumentBuilderFactoryImpl"/> <system-property javax.xml.parsers.SAXParserFactory="org.apache.xerces.jaxp.SAXParserFactoryImpl"/> <system-property javax.xml.transform.TransformerFactory="org.apache.xalan.processor.TransformerFactoryImpl"/> I've added these on the top level (under resin xml tag) since the documentation states that this is supported: http://www.caucho.com/resin-3.0/config/env.xtp#system-property This is the exception from my Java client: Exception in thread "main" org.codehaus.xfire.XFireRuntimeException: Could not invoke service.. Nested exception is org.codehaus.xfire.fault.XFireFault: Could not unmarshall type. org.codehaus.xfire.fault.XFireFault: Could not unmarshall type. at org.codehaus.xfire.fault.Soap11FaultSerializer.readMessage(Soap11FaultSerializer.java:31) at org.codehaus.xfire.fault.SoapFaultSerializer.readMessage(SoapFaultSerializer.java:28) at org.codehaus.xfire.soap.handler.ReadHeadersHandler.checkForFault(ReadHeadersHandler.java:111) at org.codehaus.xfire.soap.handler.ReadHeadersHandler.invoke(ReadHeadersHandler.java:67) at org.codehaus.xfire.handler.HandlerPipeline.invoke(HandlerPipeline.java:131) at org.codehaus.xfire.client.Client.onReceive(Client.java:382) at org.codehaus.xfire.transport.http.HttpChannel.sendViaClient(HttpChannel.java:139) at org.codehaus.xfire.transport.http.HttpChannel.send(HttpChannel.java:48) at org.codehaus.xfire.handler.OutMessageSender.invoke(OutMessageSender.java:26) at org.codehaus.xfire.handler.HandlerPipeline.invoke(HandlerPipeline.java:131) at org.codehaus.xfire.client.Invocation.invoke(Invocation.java:75) at org.codehaus.xfire.client.Client.invoke(Client.java:335) at org.codehaus.xfire.client.XFireProxy.handleRequest(XFireProxy.java:77) at org.codehaus.xfire.client.XFireProxy.invoke(XFireProxy.java:57) at $Proxy10.getDocumentInformation(Unknown Source) at no.htg.newsconductor.client.WSClient.main(WSClient.java:37)