This sort of issue happens often in databases and digital records systems - the key used as the identifying attribute of the record in the database, is already present, so it doesn't add the record anew or change the existing record - but something about the record has become corrupted so the data itself isn't useful. A work-around is being able to manually delete the corrupt record, which would result in re-registration with a new record later on- rather than flushing the entire database entirely. But such nuanced editing appears not to be possible with the MS2, or with some corrupt records in the MS2.