Error in exception(RMI)

Hi all, im trying to run so many codes using java RMI and nothing seems to work. im on the point of banging my head on the PC.

Im sure evryone is aware of the popular Calculator example: Calcuator.java, CalcuatorImpl.java, CalcuatorClient.java and CalcuatorServer.java. I hae done this and other examples at University and they executed and compiled all fine but when I run them on my own PC, I get the following error. could some one help me please.

java.rmi.ServerException: RemoteException occurred in server thread;

nested exception is:

java.rmi.UnmarshalException: error unmarshalling arguments;

nested exception is:

java.lang.classNotFoundException: Calculator

[716 byte] By [ssimkhana] at [2007-11-27 8:00:10]