I'm going completely bonkers over here . I was going to upload my assignment today but something screwy is happening . My program is currently working fine when I use http URLs and a web server for my codebase . And yesterday I had it working fine with file URLs . But for some reason it's not working anymore : I get a crash when attempting to book . It's RemoteException and it occurs precisely at database.modify(record)where record is DataInfo type . The nested exceptions are UnMarshalException and NoClassFoundException . So it appears the server is not unmarshalling DataInfo record properly because it can't find the class ? It works fine under my web server so I just don't get it . If anyone has an idea please let me know , that's all I can say .