org.jboss.ws.core.jaxws.handler.SOAPMessageContextJAXWS

If you see the following exception:
javax.xml.ws.soap.SOAPFaultException: org.jboss.ws.core.jaxws.handler.SOAPMessageContextJAXWS cannot be cast to javax.xml.rpc.handler.soap.SOAPMessageContext

it means that in your handler class, you are using javax.xml.rpc.handler.soap.SOAPMessageContext
rather than
import javax.xml.ws.handler.soap.SOAPMessageContext