SAP Message VK859 - Foreign key cannot be created for the selected field &1-&2

Diagnosis
In order to check a field or to display possible entries, the systemrequires a foreign key dependency.
The system cannot create the foreign key dependency for field &V1&-&V2&
.
The system needs other fields to check the above field. However, inthis case, the required field is missing. A check cannot be carriedout.

System Response
The system allows a missing foreign key dependency but this isdetrimental to the functionality.

Procedure
Please contact your system administrator if you cannot make therequired settings.