---
"@context": https://schema.org
"@type": TechArticle
"@id": https://www.twilio.com/docs/api/errors/14231#article
headline: "14231: Dial->Conference: Provided Attributes was not valid JSON "
url: https://www.twilio.com/docs/api/errors/14231
inLanguage: en
dateModified: 2026-06-09T11:00:42.000Z
author:
  "@type": Organization
  name: Twilio Developer Education Team
publisher:
  "@type": Organization
  name: Twilio
---

# 14231: Dial->Conference: Provided Attributes was not valid JSON 

Log Level: ERROR

## Description

This error occurs when the `Attributes` value provided for a TaskRouter-integrated `<Dial><Conference>` flow is not valid JSON. TaskRouter task attributes must be expressed as JSON, and TaskRouter uses task attributes when routing work and handling `conference` instructions for voice tasks.

### Possible causes

* The `Attributes` value is not valid JSON.
* The task attribute payload is malformed instead of being sent as a JSON string. TaskRouter task attributes must be expressed in JSON.
* The JSON was escaped or double-serialized before Twilio received it.

### Possible solutions

* Update the `Attributes` payload so it is valid JSON before you send the request or return the TwiML.
* If you create or update the related Task directly, send `attributes` as a JSON string. For example, `{ "task_type": "call", "twilio_call_sid": "CAxxx" }`.
* If you use TaskRouter `conference` instruction for a voice task, include the minimum task attributes `{"call_sid":"<callsid>","to":"<E.164 to number>"}` and keep the full payload valid JSON.
* If your application serializes the payload before sending it, make sure the JSON is not escaped.

#### Additional resources

* [Task Resource](/docs/taskrouter/api/task)
* [Task Reservation Resource](/docs/taskrouter/api/reservations)
* [TwiML `<Dial>`](/docs/voice/twiml/dial)