ClassCastException: Proxy_4 cannot be cast to Xxxxx

I encountered that error in RMI client side in EJB and the problem was in the EJB side actually .... I changed some jars in the shared library -that other apps use and needed this change- the EJB reads from, so something wrong happened in the EJB project -but nothing appeared in the log- so when
I fixed this and made a separate lib for the EJB.... every thing worked fine.

IllegalArgumentException: XxxxxBean stateless session

I encountered this error in RMI client side ... the reason was that something changed on the EJB side that required a restart in the client side ... so after I restarted the client side application the issue was resolved