ORA-04099

Error: ORA-04099: trigger 'string' is valid but not stored in compiled form

Causa: A trigger was attempted to be retrieved for execution and was found to be valid, but not stored. This may mean the an upgrade was done improperly from a non-stored trigger release.

Acción: Alter compile the trigger to create the trigger in stored form. Also, you may want to review that a proper upgrade was done.