In order to link the gift to a constituent, you must include the constituent import ID, constituent ID, or Social Security Number in the import data file. Normally, only one of the three fields is included. However, all three fields may be included. The one that is used to link the gifts to the constituent record must exactly match the information on the constituent record. For example, if selecting the import ID on the General tab of the import parameters, the import ID must exactly match the import ID of the constituent record to which the gift is being added.

If you receive this error, it indicates that this field is marked as read only or is invalid in some way. Remove it from the import data file and then re-import using the import ID. Also ensure that you are using a gift import.

For more information, review What is the unique identifier to identify existing constituents when importing? (BB87878).