CORBA35 — CORBA Exceptions

I implemented CORBA functionality, in that implementation I got some exceptions. I am sending that exceptions list in the below. omniORB: ERROR – the application attempted to invoke an operation on a nil reference. terminate called after throwing an instance of 'CORBA::INV_OBJREF' Aborted (core dumped) I have some doubts on these exceptions. What is the cause for this exception? How can I solve this exception? Please clarify my doubts.