Hi AnupamBhaglania,
This error message is not related to the code
TwitterSession session = Twitter.getSessionManager().getActiveSession();
as that just looks up session from an internal map.
This error is logged whenever we’re attempting to get a guest session. If that fails, we fallback to using an application only session. This code is done automatically for you if you’re using any of the tweet views.
If you need higher rate limits, please email support@fabric.io so we can get your account elevated, otherwise, you can safely ignore these warnings.
Lien