Same old lack of explicit serialVersionUIDs causing major incompatibilities across releases:

java: org.jnp.interfaces.NamingContext@bd0108
Looking up RemoteCalculator
javax.naming.CommunicationException [Root exception is java.io.InvalidClassException: org.jboss.ejb3.stateless.StatelessRemoteProxy; local class incompatible: stream classdesc serialVersionUID = 2583299153931800023, local class serialVersionUID = 8144530673853515126]
at org.jnp.interfaces.NamingContext.lookup(NamingContext.java:707)
at org.jnp.interfaces.NamingContext.lookup(NamingContext.java:572)
at javax.naming.InitialContext.lookup(InitialContext.java:351)
at trail.client.RemoteCalculatorClient.main(RemoteCalculatorClient.java:38)
Caused by: java.io.InvalidClassException: org.jboss.ejb3.stateless.StatelessRemoteProxy; local class incompatible: stream classdesc serialVersionUID = 2583299153931800023, local class serialVersionUID = 8144530673853515126
at java.io.ObjectStreamClass.initNonProxy(ObjectStreamClass.java:519)
at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1546)
at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1460)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1693)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1299)
at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1912)
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1836)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1713)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1299)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:339)
at java.rmi.MarshalledObject.get(MarshalledObject.java:135)
at org.jnp.interfaces.MarshalledValuePair.get(MarshalledValuePair.java:57)
at org.jnp.interfaces.NamingContext.lookup(NamingContext.java:637)