The Swing Client runs without errors on any Windows machines (only jre 1.6.0 and network contact installs to the JBoss of the Vista machine). An exception is thrown with the Swing Client on the Debian machine, here: initial.lookup("project_projectQ"); The exception reads: javax.naming.CommunicationException [Root exception is java.lang.ClassNotFoundException: project.query.projectQHome] The project.query.projectQHome is an interface in a file project.ear, which is on the JBoss (the Vista machine) deployed. | package project.query; | public interface projectQHome extends javax.ejb.EJBHome { | public projectQ create() throws java.rmi.RemoteException, javax.ejb.CreateException; | } | If this interface in the .jar file of the Swing Client is merged, the functions run also on the Debian machine!! Why doesn't run the interface project.query.projectQHome from project.ear the JBoss on Debian machine? Are there Threads, which miss communication and/or the download of the interface run? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4193323#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...