Document entered is not a shipping notification

What causes this issue?

The system found that the document specified is not a
<DS:GLOS.shipping_notification>shipping notification</>.

System Response

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

How to fix this error?

INCLUDE NA_EINGABE_PRUEFEN
Do you want to <DS:TRAN.VL33>Search for shipping notification</>?

Error message extract from SAP system. Copyright SAP SE.