This is a long shot. Disable automatic date/time, set your phone's calendar to , then try logging in. The server may incorrectly validate the old certificate. (Rarely works today, but worth a try.)
Facebook Paper was a standalone mobile app launched in 2014 designed to provide a more immersive, magazine-like experience for your News Feed. Availability : Facebook officially shut down Paper on July 29, 2016 download facebook version 2.2.1