Make an entry in the required field &

What causes this issue?

Field &V1& of parameter &V2& does not contain an entry. However, this
field is a required field. Refer to the documentation for BAPI &V3& to
see how the field should be filled correctly.

System Response

The BAPI cannot be processed correctly.

How to fix this error?

Enter a value in field &V1& of parameter &V2&.

Error message extract from SAP system. Copyright SAP SE.