SAP Message 5Z452 - The reference personnel number &1 has an invalid format

Diagnosis
The reference personnel number is saved on the database as a 12-digitnumerical field. The first 8 characters of the reference personnelnumber must be numbers and the last 4 characters must be blank. Onlythen can the reference personnel number refer to a personnel numberthat is valid in the system.
The first 8 characters &V2& of the reference personnel number &V1& arenot only digits.

System Response
Due to the different date format, the incorrect personnel number is notdisplayed in the RefPersNr field. If no entry can be made in thefield, a 0 is displayed. Otherwise, the field is blank.

Procedure
If no enty can be made in the RefPersNo field, a warning isdisplayed. If an entry can be made, you must enter a new, correctreference personnel number. The search help for the field RefPersNo
gives a selection of valid reference personnel numbers.