Did you try the JGroups demo program using the same cluster configs? Also do you have a more detailed stack trace? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4117963#4117963 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=4117963