Unresolved class 'MyFirebaseMessagingService' Android Studio

See this image first

check if Firebase classes are in correct package folder. example if firebase classes are in package 'services' then in manifest service would have android:name=".services.FirebaseMessagingService" then Unresolved class 'MyFirebaseMessagingService' error will get solved.

<service
    android:name="com.google.firebase.messaging.FirebaseMessagingService"
    android:exported="false">
    <intent-filter>
        <action android:name="com.google.firebase.MESSAGING_EVENT" />
    </intent-filter>
</service>

Giving full path for this lib name com.google.firebase.messaging.FirebaseMessagingService fixed this issue.