While sending a Purchase Order(PO) to SAP Business Network, my PO fails with the below error: PO-9: Invalid cXML response.

Prod or Test account.

The supplier's commerce eXtensible Markup Language (cXML) application is sending back an invalid cXML response for the order posted by Ariba.

The following is an example of an invalid cXML response:

<?xml version="1.0" encoding="UTF-8" ?><!DOCTYPE cXML SYSTEM "http://xml.cxml.org/schemas/cXML/1.1.010/cXML.dtd"><Response>
<Status code="500" text="Unrecognised message request"/>
</Response>

The supplier has 2 options to correct this.

Enter a valid email address in their Settings > Electronic Order Routing
Change the Routing Method in their Settings > Electronic Order Routing to a different method (such as Online)
Once corrective action has been taken, the supplier can resend the PO to themselves.

Also The supplier's application needs to send back a valid 200 acknowledgment for the order posted by Ariba.

The following is an example of a valid 200 response:

<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE cXML SYSTEM "http://xml.cXML.org/schemas/cXML/1.2.021/cXML.dtd"> <cXML payloadID="1232424-testpayloadid234525"xml:lang="en-CA" timestamp="2016-10-12T18:39:42-08:00">
<Response>
<Status code="200" text="OK"/>
</Response> </cXML>

See Purchase orders are failing to reach the supplier integrated system (via cXML), but can be seen in the supplier's Inbox for a list of common similar errors and their resolution.

SAP Business Network for Procurement & Supply Chain > Transaction Documents > Transaction (Purchase Orders, Ship Notices & Goods Receipts)