title: Game crashes with error as - > onRealTimeMessageSent(Unknown Source)
body: <p>Did anyone come across this type of error ?? 
  This thing happens after the message is sent succesfully to the other device ..</p>
  
  <pre><code>01-30 14:20:38.894: E/AndroidRuntime(6258): FATAL EXCEPTION: main
  01-30 14:20:38.894: E/AndroidRuntime(6258): java.lang.NullPointerException
  01-30 14:20:38.894: E/AndroidRuntime(6258): at com.google.android.gms.games.GamesClient$29.onRealTimeMessageSent(Unknown Source)
  01-30 14:20:38.894: E/AndroidRuntime(6258): at com.google.android.gms.internal.ex$am.a(Unknown Source)
  </code></pre>
  
  <p>Code i have used to send message to the others participants : </p>
  
  <pre><code>for (Participant p : mParticipants)
  {
      if (p.getParticipantId().equals(mMyId))
          continue;
      if (p.getStatus() != Participant.STATUS_JOINED)
          continue;
  
      if(p.isConnectedToRoom()) 
      {   
          getGamesClient().sendReliableRealTimeMessage(null, msgData, mRoomId,p.getParticipantId());
      }          
  }
  </code></pre>
  
  <p>Can someone please explain me why is it coming as unknown source ??</p>