---
"@context": https://schema.org
"@type": TechArticle
"@id": https://www.twilio.com/docs/api/errors/52118#article
headline: "52118: FCM Bad Request"
url: https://www.twilio.com/docs/api/errors/52118
inLanguage: en
dateModified: 2026-03-11T20:43:38.000Z
author:
  "@type": Organization
  name: Twilio Developer Education Team
publisher:
  "@type": Organization
  name: Twilio
---

# 52118: FCM Bad Request

Log Type: APPLICATION

Log Level: ERROR

## Description

### Possible causes

* Invalid or missing registration token.
* Incorrectly formatted JSON payload.
* Invalid or missing required fields in the request.
* Exceeding the payload size limit.
* Invalid API key or authentication token.

### Possible solutions

* Verify that the registration token is correct and not expired.
* Ensure the JSON payload is correctly formatted and adheres to FCM specifications.
* Check that all required fields are included and correctly populated in the request.
* Ensure the payload size does not exceed the maximum limit allowed by FCM.
* Verify the API key or authentication token is valid and has the necessary permissions.