Hi For information to anyone else I am now closing this.
Although I don't have a comprehensive understanding of what was actually occurring what I do know is that it was only occurring when I had configured a servlet filter (just for logging response times taken between before doFilter and after doFilter) to also apply to my JAX-RS requests. Removing the filter config from my JAX-RS requests stopped the errors occurring. -- View this message in context: http://apache-wink-users.3471013.n2.nabble.com/Using-MessageBodyWriter-in-WebSphere-with-Session-cookies-enabled-tp7572816p7572818.html Sent from the Apache Wink Users mailing list archive at Nabble.com.
