SAP Message W8520 - Conversion only possible for field restrictions without entry KEY

Diagnosis
The existing field restrictions cannot be converted, since they containeither the keyword KEY or values in the fields CUKY_NEW, CUKY_OLD,UNIT_NEW, UNIT_NEW.

Procedure
Conversion to a combined field restriction is not yet supported forfield restrictions of this kind. You can, therefore, only change theexisting field restrictions or add/delete other field restrictions.