I can not get registration ID from Android GCM

Although I try other answer about this problem, it can't be solved. Sender ID is correct, permissions are added, API key is true.

I use this post for creating the project: http://developer.android.com/guide/google/gcm/gs.html#server-app

    GCMRegistrar.checkDevice(this);
    GCMRegistrar.checkManifest(this);
    String regId = GCMRegistrar.getRegistrationId(this);
    if (regId.equals("")) {
      GCMRegistrar.register(this, SENDER_ID);
      regId = GCMRegistrar.getRegistrationId(this);
    } else {
      Log.v(TAG, "Already registered");
    }
    String did = getDeviceID();

it returns empty string.