Flight is not archivable; invoices cannot be created for flight bookings.

What causes this issue?

The "archivable" status cannot be set for this flight. It was not
possible to create invoices for all flight bookings of this flight.

System Response

How to fix this error?

The business process has not been completed. The "archivable" status can
only be set for this flight, when invoices have been created for all of
its flight bookings.
Contact the person responsible for this flight.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.