When using the Participant destination, you cannot add the same constituent as a participant more than one time due to Raiser's Edge functionality.   You can, however, update existing participations with attributes and other mappings if those have been linked to the Participant mapping.


Normally, you should not see this exception for an existing participant record as that record should be set to Update in the Review screen.  However, if an existing constituent already has a participant record for an event, but that participant record is set to Create in the review screen, this exception will indicate that you cannot Create a new Participant record that would duplicate the existing record.


To resolve this issue if you have not yet imported, you should exit the Review screen and allow Importacular to match the data in your import to the data in the Raiser's Edge again (do not use a saved Review session for this).


To resolve this issue if you have imported, use your Control Report as your data source.