API error code 10209 indicates that a BAUpdate or DoReference Transaction call was used but Preapproved Payments (PAP) isn't enabled for the merchant. This applies only to deprecated PAP billing agreements.
Preapproved Payments is no longer an available product for our merchants. Alternative options are available, such as Reference Transactions or PayPal for Partners.
See the Developer Portal for a complete list of NVP/SOAP API error codes.