As of Android SDK version 4.11, Swrve supports Firebase Cloud Messaging (FCM) and as of version 6.0, we have completely removed support for Google Cloud Messaging (GCM). If you are integrating the Swrve SDK into a new app and want to use FCM, follow the steps outlined in the Android Integration guide. If you are upgrading the SDK and currently use Google Cloud Messaging (GCM), you need to properly migrate your existing GCM app to FCM. This will ensure you can continue to use existing GCM tokens in FCM.

For existing GCM users, the best migration consists of importing the old project into the Firebase Console. This will allow you to target both the old and new client, since the sender-id will not change. For detailed instructions on how to migrate your GCM app to Firebase, see the Google Developer article, Migrate a GCM Client App for Android to Firebase Cloud Messaging.