Archiving not possible; business partner still used in &1

What causes this issue?

Business partner &V2& is used in Real Estate object &V1&.

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

System Response

Archiving of this business partner is not possible.

How to fix this error?

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.