What LND saying is true. I went back and look at full export log which my co-worker did couple of weeks ago. It didn't export MDSYS user... even in full export. She Claims it doesn't need to export MDSYS still the database on which she imported works fine, as context catridges option also holds the objects that are owned by MDSYS. Not a posting that answers Q, thought it would be help full for further investigation of the isse.