SAP Message V4002 - The delivery entered does not exist in the document flow

Diagnosis
You have entered the delivery note number for the last delivery noteposted for this customer. Because it could not be found in the documentflow, it is impossible to find an exact starting point for cumulativequantity determination.

System Response
The system does not except the entry or generates a warning message.

Procedure
Please check to see whether the delivery note number was enteredcorrectly or select a delivery note number available in the documentflow.
Please remember that correct starting point for the cumulative quantitydetermination is necessary in determining the correct deliveryquantity.