i am attempting to include a client side handler with my service call. The client is deployed and the application-client and error are below. Things work fine with a server side handler. When I comment out the handler, the web service works fine. What is wrong here? application-client xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/application-client_1_4.xsd" version="1.4"> <display-name>webservice client</display-name> <service-ref> <service-ref-name>service/s</service-ref-name> <service-interface>com.s.S</service-interface> <wsdl-file>META-INF/s.wsdl</wsdl-file> <jaxrpc-mapping-file>META-INF/mapping.xml</jaxrpc-mapping-file> <handler-name>SHandler</handler-name> <handler-class>com.s.SHandler</handler-class> </service-ref> </application-client> javax.naming.NamingException: Cannot unmarshall service ref meta data, cause: java.io.InvalidClassException: org.jboss.ws.metadata.j2ee.UnifiedHandlerMetaData; local class incompatible: stream classdesc serialVersionUID = -3019416564080333900, local class serialVersionUID = 8000854586742278995 at org.jboss.ws.jaxrpc.ServiceObjectFactory.getObjectInstance(ServiceObjectFactory.java:126) at javax.naming.spi.NamingManager.getObjectInstance(NamingManager.java:304) at org.jnp.interfaces.NamingContext.getObjectInstance(NamingContext.java:1125) at org.jnp.interfaces.NamingContext.getObjectInstanceWrapFailure(NamingContext.java:1142) at org.jnp.interfaces.NamingContext.lookup(NamingContext.java:705) at org.jnp.interfaces.NamingContext.lookup(NamingContext.java:587) at javax.naming.InitialContext.lookup(InitialContext.java:351) at com.Client.main(Client.java:59) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4000107#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...