Oracle Message TNS-12208 - TNS: could not find the TNSNAV.ORA file

ERRORTNS: could not find the TNSNAV.ORA file
CAUSEEither the ORACLE environment is not set up correctly, or the TNSNAV.ORA file is not present.
ACTIONEnsure that the ORACLE environment is set up appropriately on your platform and that a TNSNAV.ORA file is present.