I believe that I have found a solution to this problem (at least in my case). It seems that I have some private, SEAM-injected properties in the Session Bean object that JBOSS wwas trying to passivate. For example: @In (value="folderTreeBacker", create=true) private FolderTreeLocal folderTree; I have added the "transient" keyword to stop them being serialised, as follows: @In (value="folderTreeBacker", create=true) private transient FolderTreeLocal folderTree; After doing this, the javax/portlet/PortletContext problem no longer occurs on my system. Richard. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3989968#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...