16011: Conference Event: Error Response to Callback URL

Twilio returns This error when it receives an error response while sending a conference event to the callback URL configured on the conference. Conference events are sent to the statusCallback URL, and the events that trigger those requests are controlled by statusCallbackEvent. Twilio expects status callback webhooks to return a simple 200 OK response.

• The statusCallback URL configured for the conference is incorrect, or the first participant set a different URL than the one you intended, because later participants cannot override it.
• Your webhook endpoint returned a non-200 OK response, such as a 4xx or 5xx, when Twilio sent the conference event callback.
• Your webhook handler does not accept the request method Twilio is using. For conference status callbacks, statusCallbackMethod defaults to POST.

• Verify the statusCallback URL for the conference and make sure the first participant to join supplies the correct value, since later statusCallback values are ignored.
• Update your webhook handler so it successfully receives the conference event request and returns 200 OK.
• Confirm the endpoint accepts the configured request method, and use POST unless you explicitly configured a different statusCallbackMethod.

• TwiML Voice: <Conference>
• Voice Conference
• Webhooks FAQ