title: Firebase Realtime Database doesn't update values
body: <p>I have been writing an app using firebase database and for the last two days, it doesn't work.
  What I mean by this is that I have a connection to the database, but when I try to read information by setting <code>addListenerForSingleValueEvent</code> it doesn't run the <code>ValueEventListener</code> even though I <code>updateChildren</code>.<br></p>
  
  <pre><code>        DatabaseReference mBlaze = FirebaseUtil.getDatabase(PLACES);
          mBlaze.addListenerForSingleValueEvent(new ValueEventListener() {
              @Override
              public void onDataChange(DataSnapshot dataSnapshot) {
                  for (DataSnapshot snapShot : dataSnapshot.getChildren()) {
                      System.out.println("Hello");
                  }
              }
  
              @Override
              public void onCancelled(DatabaseError databaseError) {
                  System.out.println("Error");
              }
          });
          long sTime = System.currentTimeMillis();
          while (!triggers[0])
              if (System.currentTimeMillis() - sTime &gt; 5000)
  </code></pre>
  
  <p>I have a trigger value in the database used just to run the <code>addListenerForSingleValueEvent</code>.
  <br><br>
  If I try to run this on my device\emulator, it won't print out the message "Hello", nor will it print out the message "Error".<br>
  The reason this is a problem is that I am trying to verify a code against the firebase database.
  I give it a 5 second time window for the the value to change, meaning the code was found, and if after 5 second the value of <code>triggers[0]</code> doesn't change, it means the code isn't valid.<br></p>
  
  <p>During my attempts to reduce the code I have stumble upon the <code>setLogLevel</code> which after I used it with <code>Level.DEBUG</code>, I have found that this line appears over and over again:</p>
  
  <blockquote>
    <p>Error fetching token: The user's credential is no longer valid. The user must sign in again.</p>
  </blockquote>