# Troubleshooting Android, Chrome, Firefox errors
| Error | Description | What to do |
| -------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| **AuthenticationError** | FCM authentication failed due to invalid credentials. | Check that the credentials, ServerKey, and SenderID specified in the Pushwoosh Control Panel are correct. |
| **DisabledFirebaseAPI** | Sending pushes via the new HTTP v1 protocol is disabled in the FCM console. | Enable sending push notifications in the FCM Console using the new HTTP v1 protocol. |
| **EmptyCredentials** | Failed to send a push notification using any of the specified credentials. The credentials specified in the Pushwoosh Control Panel are invalid. | Reconfigure the platform (_Settings_ → _Configure platform_). |
| **FCMInternalServerError** | FCM failed to deliver the message to the device. This usually means that the FCM service is temporarily unavailable. | Try again after a while. |
| **FrequencyCapping** | The device was filtered by [Frequency Capping](/product/messaging-channels/global-frequency-capping). | If such behavior was not intended, check the [Frequency Capping](/product/messaging-channels/global-frequency-capping) settings. |
| **InternalServerError** | FCM failed to deliver the message to the device. This usually means that the FCM service is temporarily unavailable. | Try again after a while. |
| **InvalidCredentials** | When configuring the platform, you added incorrect JSON with FCM credentials or specified incorrect SenderID or ServerKey. | Reconfigure the platform using the correct credentials, SenderID, and ServerKey from the FCM Console. |
| **InvalidEndpoint** | This is an internal FCM error that means the push is sent to an invalid address. | Try again after a while. |
| **InvalidPrivateKey** | The private key specified in the _private\_key_ field in the FCM credentials has an invalid structure. | Reconfigure the platform in the Pushoowsh Control Panel and re-upload JSON with credentials. |
| **InvalidRegistration** | The push token is invalid; the device will be unsubscribed from notifications. | Use the valid token and check whether you have enabled notifications from your app on the device. |
| **MessageTooBig** | Message size exceeds the 4096 bytes FCM limit. | Reduce the size of the message you send. |
| **MistmatchSenderId** | The error occurs for one of the following reasons:
- The sender ID specified in your app does not match the sender ID specified in the Pushwoosh Control Panel when configuring the platform.
- The sender ID in your app does not match the sender ID associated with the FCM credentials you used.
| Ensure you are using a valid sender ID from Firebase Console in your application and Pushwoosh platform configuration. |
| **NotFound** | This is an internal FCM error that means the FCM service is currently unavailable. | Try again after a while. |
| **NotRegistered** | Device is not registered. This status means one of the following:
- The device was unsubscribed from notifications;
- The application was deleted from the device;
- The push token of the device has expired.
| Try using a new token. |
| **PermissionDenied** | Credentials specified in the Pushwoosh Control Panel do not grant permission to send push notifications. This means that push notifications cannot be sent from this FCM account. | Get the credentials with the correct permissions according to the [Firebase documentation](https://firebase.google.com/docs/projects/iam/permissions). When generating credentials to send messages, you must have the Firebase Admin role or a role with the _‘cloudmessaging.messages.create’_ permission. |
| **SenderIDMistmatch** | The error occurs for one of the following reasons:
- The sender ID specified in your app does not match the sender ID specified in the Pushwoosh Control Panel when configuring the platform.
- The sender ID in your app does not match the sender ID associated with the FCM credentials you used.
| Ensure you are using a valid sender ID from Firebase Console in your application and Pushwoosh platform configuration. |
| **TokenIsEmpty** | The following reasons can cause the error:
- The device does not have a token.
- The token was not transmitted when registering the device.
- When the request was sent, the device did not have a token, but for some reason, it was transmitted to our device database.
| If you see this error frequently, please contact our [Customer Support Team](https://help.pushwoosh.com/hc/en-us/requests/new/?utm\_content=docs\&utm\_term=post\&utm\_campaign=android-chrome-firefox-errors). |
| **Unavailable** | Failed to send the message to FCM after several attempts. This usually means that the FCM service is temporarily unavailable. | Try again after a while.
If you see this error frequently, please contact our Customer Support Team.
|
| **Unregistered** | Device is not registered. This status means one of the following:
- The device was unsubscribed from notifications;
- The application was deleted from the device;
- The push token of the device has expired.
| Try using a new token. |
| **UnsupportedTokenType** | The token is invalid; the device will be unsubscribed from notifications. | Use the valid token. |