Fixing and API error

I'm submitting a Wufoo form via the API and I am getting this in the zohoResponse.log file. The mandatory field is the 'RMA - Customer Name' which is hardcoded into the PHP file and it appears to be passed. Any ideas why it still throws the 4401 error?

<?xml version="1.0" encoding="UTF-8" ?>
<response uri="/crm/private/xml/Campaigns/insertRecords"><error><code>4401</code><message>Unable to populate data, please check if mandatory value is entered correctly.</message></error></response>

<Campaigns><row no="1"><FL val="RMA - Customer Name">RMA Contact Form</FL><FL val="RMA - Customer Owner">First Last</FL><FL val="Description">Wufoo Test2</FL><FL val="Email">wufootest2@gmail.com</FL><FL val="Phone">6035555555</FL><FL val="Bar Code">456789</FL><FL val="Invoice Num">453456</FL><FL val="Invoice Date">20160914</FL><FL val="OS">Win</FL><FL val="Cust Issues">Test</FL><FL val="Accepted Terms">I accept the RMA Policy</FL></row></Campaigns>