EJB Adapter returning null or empty

Does anybody know why this error occurs while configuring new operation on EJB adapter in EI.

Not Available (516-5163): The adapter process was unable to supply a set of valid values for the following reason: EJBServer.getSingleRemoteMethodList - inBean.getHomeClass() is null or empty

com.wm.adapter.ejb.server.EJBAdapterException: EJBServer.getSingleRemoteMethodList - inBean.getHomeClass() is null or empty 

Adnan