title: Warning: "Missing_InstanceID_Service"
body: <p>I just started using Firebase for Android and I have hardly and code in the application but I am getting this warning in the console:</p>
  
  <pre><code> D/FirebaseInstanceId: background sync failed: MISSING_INSTANCEID_SERVICE, retry in 80s
  </code></pre>
  
  <p>I have done very little reading from the database in the application and have not gotten any data back, so I figure this might be why. I believe I set the application up correctly so how should I go about fixing this warning? </p>
  
  <p>Thank you very much for all help and support!</p>
  
  <p>And in case you were wondering, this is my code:</p>
  
  <pre><code>FirebaseDatabase firebase;
  DatabaseReference userRef;
  
  @Override
  protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_login);
  
       firebase = FirebaseDatabase.getInstance();
       userRef = firebase.getReference("Users");
  
      System.out.println("\n\n\n"+userRef+"\n\n\n");
  
      userRef.addValueEventListener(new ValueEventListener() {
  
          @Override
          public void onDataChange(DataSnapshot dataSnapshot) {
              // This method is called once with the initial value and again
              // whenever data at this location is updated.
              String value = dataSnapshot.getValue(String.class);
              //Log.d(TAG, "Value is: " + value);
          }
  
          @Override
          public void onCancelled(DatabaseError error) {
              // Failed to read value
             // Log.w(TAG, "Failed to read value.", error.toException());
          }
  
  
  
  
      });
  
  }
  </code></pre>
  
  <p>Dependencies:</p>
  
  <pre><code>dependencies {
      compile fileTree(dir: 'libs', include: ['*.jar'])
      testCompile 'junit:junit:4.12'
      compile 'com.android.support:appcompat-v7:23.2.1'
      compile 'com.google.firebase:firebase-database:9.2.1'
      compile 'com.google.firebase:firebase-auth:9.2.1'
  }
  </code></pre>