Fixing warnings and errors after running impdp

First check the registry to see if the list of invalid objects by running the query below and see which objects have status set to INVALID:

SELECT comp_id, version, status FROM dba_registry;

or simply do:

SELECT COUNT(*) FROM dba_registry WHERE status='INVALID';

If there are any invalid objects, run utlrp script located in which is located in $ORACLE_HOME/rdbms/admin/utlrp.sql. This scrip will recompile inalid objects.

@?/rdbms/admin/utlrp.sql

The line above will run the script.

Next step is to check dba_registry again to see if all invalid objects have been fixed.