---
"@context": https://schema.org
"@type": TechArticle
"@id": https://www.twilio.com/docs/api/errors/50513#article
headline: "50513:  Message author should be among Group MMS participants."
url: https://www.twilio.com/docs/api/errors/50513
inLanguage: en
dateModified: 2026-03-11T20:43:38.000Z
author:
  "@type": Organization
  name: Twilio Developer Education Team
publisher:
  "@type": Organization
  name: Twilio
---

# 50513:  Message author should be among Group MMS participants.

Log Type: APPLICATION

Log Level: ERROR

## Description

Author identity or address not found among Group MMS participants.

### Possible causes

* Provided author Address is not among Group MMS participants.
* Provided author Identity is not among Group MMS participants.

### Possible solutions

* Check that the Author is participant of Group MMS conversation.