Firebase, cannot query Token and "onTokenRefresh()" is not called

Question

1.) The "onTokenRefresh()" Method in "FirebaseInstanceIdService" is never called.

2.) If I want to get the Token in the Activity I get the following error:

06-08 11:25:14.871  16684-16684/com.xxx.test W/System.err﹕ java.lang.IllegalStateException: FirebaseApp with name [DEFAULT] doesn't exist.
    06-08 11:25:14.871  16684-16684/com.xxx.test W/System.err﹕ at ahl.a(Unknown Source)
    06-08 11:25:14.871  16684-16684/com.xxx.test W/System.err﹕ at ahl.e(Unknown Source)
    06-08 11:25:14.871  16684-16684/com.xxx.test W/System.err﹕ at com.google.firebase.iid.FirebaseInstanceId.a(Unknown Source)

I've added the services in my Manifest correctly:

<service
            android:name="com.xxx.services.firebase.messaging.MyFirebaseMessagingService">
        <intent-filter>
            <action android:name="com.google.firebase.MESSAGING_EVENT"/>
        </intent-filter>
    </service>
    <service
            android:name="com.xxx.services.firebase.messaging.MyFirebaseInstanceIdService">
        <intent-filter>
            <action android:name="com.google.firebase.INSTANCE_ID_EVENT"/>
        </intent-filter>
    </service>

I've also added apply plugin to build.gradle file in "app"-directory:

    apply plugin: 'com.android.application'

android {
  // ...
}

dependencies {
  // ...
  compile 'com.google.firebase:firebase-messaging:9.0.2'
}

// ADD THIS AT THE BOTTOM
apply plugin: 'com.google.gms.google-services'

And the google-services plugin to build.gradle in the "root" directory:

buildscript {
    // ...
    dependencies {
        // ...
        classpath 'com.google.gms:google-services:3.0.0'
    }
}

Answer 1

My problem was the Manifest merger.

If I use the

xmlns:tools="http://schemas.android.com/tools"

and

tools:node="replace"

Please find a detailed answer here: https://stackoverflow.com/a/37831267/4291264