"java.io.IOException: Unable to deserialize the Subjects in this Context" using Web Services in WebSphere Portlet Factory Designer

Interesting, one of my colleagues has been using WebSphere Portlet Factory Designer 6.1.5 and WebSphere Portal Server 6.1.5 to continue the development of some portlets on which I'd previously worked back in April.

However, he found that he was getting exceptions such as: -

java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:79)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:618)

Caused by: com.bowstreet.webapp.engine.actions.MethodExecutionException: Error in method getPatientDetails.executeOperation. Error in method GetDemographicsExecute. Error in method GetDemographics.invoke. Error in method GetDemographics.invokeInternal. java.io.IOException: Unable to deserialize the Subjects in this Context [Root exception is javax.xml.ws.WebServiceException: java.io.IOException: Unable to deserialize the Subjects in this Context]
at com.bowstreet.webapp.engine.actions.MethodAction.callAction(MethodAction.java:122)
at com.bowstreet.webapp.engine.WebAppAccessImpl.callMethod(WebAppAccessImpl.java:405)
at com.bowstreet.webapp.engine.WebAppAccessImpl.callMethod(WebAppAccessImpl.java:302)
at genjava._requestPatientDetails.getPatientDetailsGetDemographics(_requestPatientDetails.java:80)

etc. when he attempted to execute one of the portlets ( one consumes a portlet that consumes a web service from a different, third, WPF model ).

I'd tried, and failed, to reproduce the problem using a clean installation of WPFD and WP 6.1.5 on my Ubuntu box.

After some trial and error, I asked the right question - did he use any WebSphere Feature Packs such as: -

Utility: Feature Pack for Web Services for WebSphere Application Server V6.1

Utility: Feature Pack for EJB 3.0 for WebSphere Application Server V6.1

I was prompted to do so by a previous encounter with the Web Services Feature Pack: -

http://portal2portal.blogspot.com/2009/11/wsws7007e-and-wsvr0501e-conflict.html

Lo and, if you will, behold, he was using BOTH of the above.

Given that the exception related to javax.xml.ws.WebServiceException, I'm guessing that the WS Feature Pack *MIGHT* be responsible.

He's going to test on a clean installation of WAS/WP, and will report back.