Timed Text language does not match language code specified in the Source Request.
Verify the contents of the delivered file and compare the language present to the language code used in the Source Request. If the contents of the delivered file contains the correct language needed to fulfill the Source Request, please reach out to your Netflix representative via the Backlot to confirm which language code was selected during upload through the Backlot Delivery UI.
If an incorrect language code was selected during your delivery, then the issue can be corrected by performing a metadata only redelivery. Please reach out to your Netflix representative via Backlot to have them update the Source Request to "metadata only." They will communicate when you can then perform the redelivery.