SAP Message UX289 - External number must be entered for internal number assignment

Diagnosis You want to transfer a record designated for internal numberassignment. No value was transferred for the field EXTPARTNR. Thismeans that there would be no way of finding this record in the system,since the link to the external number that is known by the user wouldbe missing. System Response The transfer is rejected. Procedure Transfer the external number for this record.