The provided XML does not conform to the Twilio Markup XML schema. Please refer to the specific error and correct the problem.
- misspelled verbs
- incorrect case for verbs; TwiML is case-sensitive, so <Say> works, but <say> will not
- misspelled or unknown attributes
- unknown or unexpected nested elements.
- check the line and column reported by the warning to see what part of your XML response caused the complaint
- verify that your application server is accepting and properly responding to any custom parameters you may be passing