i updated my lumia 535 to windows 10 using windows Insider. after updating my phone i observed some problems so i revert back to windows 8.1 after 1 year. now Facebook & Messenger doesn't work on my phone. when i open Facebook app it shows me "sorry, there was an error". when i try to open Messenger app then it shows me "REST API is deprecated for versions v2.1 and highre (12). have anybody any solution please?