Enter delivery note for evaluated receipt settlement

What causes this issue?

For this purchase order
<DS:GLOS.evaluated_receipt_settlement>evaluated receipt settlement</>
is active. The system creates the invoice document automatically based
on the goods receipt data. The invoice document should contain the
vendor's delivery note number.

System Response

Depending on how the system is configured, this message can either be a
warning or an error message.

How to fix this error?

You can maintain the delivery note on the initial screen or on the
header screen.
Choose <LS>Goto -> Additional functions -> Header</> and enter the
delivery note number.

Error message extract from SAP system. Copyright SAP SE.