When you deploy an unpackaged war containing web services, the deployment process copies web.xml to web.xml.org and then alters the <servlet-class> element inside web.xml to be:

<servlet-class>org.jboss.webservice.server.ServiceEndpointServletJSE</servlet-class>

If this modified web.xml file is then changed, the URLDeploymentScanner notices and redeploys the war. The resulting deployment process then uses the org.jboss.webservice.server.ServiceEndpointServletJSE as the implementation class of your web service which causes a NoSuchMethodException to be thrown when you call methods on your client proxy.