This error indicates either a custom designee or the default "write-in designation default" designee needs to be cross referenced. To resolve this:
  1. Cross reference the designee mentioned in the error
    1. Navigate to Data Management > Luminate Configuration
    2. Click the Cross References button
    3. Click Configure next to Gift Designation
    4. Click Create (Or Configure) for the appropriate desginee under the Items Not Referenced tab
    5. Select the appropriate value from the External Mappings Designation section
    6. Click Finish
  2. Rebuild the Errors