3742135 - Error: PO-8: Received cXML response 401 indicating an error.

Purchase Orders (PO) are failing to reach the supplier integrated system, the PO History tab on the supplier SAP Business Network account shows the error message below.

PO-8: Received cXML response 401 indicating an error.  ?

Order Type: OrderRequest.New

Routing Method: cXML

URL: https://[XXXX]

SAP Business Network

PO-8, cxml response 401, failed purchase order, failed status, cxml, order request. new, posting url, external url, invalid url, supplier routing, http 401, xml errors, resend purchase order, order routing configuration, ariba supplier account , KBA , SBN-AN-TX-POA , Transaction (Purchase Orders, Ship Notices & Goods Receipts) , Problem