Sorry for mixing up REST and SOAP in the previous message.
Nevertheless, do you also have this error if you generated the libs with ivy. ...which provides a single JAR, and not any
src_ws output as in your screen. Furthermore, is there a difference if you call it with the standard ws-element? Do you only have this problem in pure java usage or also in normal process calls?
Anyway, using the generated CXF-Client in plain Java is not a feature we tested or recommend in any way. There are a lot of features implemented to support and improve the actual JAX-WS/CXF call so that it run's in a performant and monitorable way. All that will be lost if you do it on your own ... and very likely problems will only occur in a late stage in production, where nobody want's to see it.