There is a bug into Remoting leasing... We are working into getting it fixed. So.. if you restart your server, your client has to be restarted also. If you restart your server but if you keep the client alive, Leasing will keep pinging the server while the server is still starting, and Remoting didn't have a proper isolation in one variable, hence the NPE. On my tests if you always restart your client with your server, you never get this failure. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3985844#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...