---
page_type: error
code: 52102
message: "52102: Invalid GCM/FCM registration token"
level: ERROR
product: Notifications
---

## Error - 52102

### Invalid GCM/FCM registration token

#### Possible Causes

- Invalid GCM/FCM registration token provided via the Android SDK or the REST API.

#### Possible Solutions

- Make sure you do not modify the registration token before providing it to Twilio via the SDK or the REST API.
- If you are using a command line tool to provide the registration token, make sure that it is URL-encoded.