I have implemented a ConnectionFactory which returns a DataInterface. The client can use this reference for invoking the Data class methods. The client has 2 stubs -ConnectionFactoryImpl_Stub and Data_Stub. This is the detail of Factory and Data. interface ConnectionFactory extends Remote class ConnectionFactoryImpl extends UnicastRemoteObject implements ConnectionFactory interface DataInterface extends Remote class Data extends UnicastRemoteObject implements DataInterface Without the presence of Data_Stub, there is an UnmarshallException and ClassNotFoundException Data_Stub in the client. Is it right that all clients should have a copy of Data_Stub?