Can you kindly advise what social media app you are trying to chat from (e.g facebook, Whatsapp, etc) and we will try and advise as to what exactly must be causing the issue. Otherwise, clearing cache has been known to resolve common glitches off apps. To do this, navigate to Settings > Apps > All > locate the social media app name (like Facebook) and tap it > then tap clear cache > confirm and go and retry the app by launching it from the home screen or from the app drawer. Reply using the comment button below should need still be and we will gladly assist further.