This error is generally tied to constituents that have either been removed in Luminate Online or LCRM at some point and have mismatched Member IDs. This will prevent the contact and associated donations from synching to LCRM. To resolve this error, the IDs will need to be adjusted in the database so that the record in Luminate Online can link to the record in LCRM. Contact Support and reference this article number. Support will have the database records fixed so that this error can be rebuilt and the records will sync correctly.