Hello, There is a problem for me with the interceptors (adding some metadata) during an EJB3 method invocation. I thought it is an issue with the serialization framework so had a conversation with Clebert before in this forum: http://www.jboss.com/index.html?module=bb&op=viewtopic&t=89387. So I will give an abstract. The complete stacktrace and code snippets are given in the serialization forum. I created an clientside and an serverside interceptor. The clientside interceptor put a string in the SimpleMetaData with the default payload key MARSHALLED and the serverside interceptor should read this data. So if I do this I get allways a ClassCastException (shown in the other forum) with JBoss-4.0.4 and newer but not with JBoss-4.0.3SP1 (That works fine). If I set the payload key to AS_IS then it works fine with the newest version. I would like to know what I do wrong or understand wrong that I allways get this ClassCastException? If you need more information, testcases (I added a url where you can find a complete example) ore something please let me know. Thanks in advance, Thomas Termin View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3974945#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...