Ways to fix Messenger not working 

In case Facebook messenger is currently not working on your phone then don't worry, because here we have a couple of solutions to fix Facebook messenger not working you just need to follow our step by step guide below till you get rid out of this issue.

1. First of all restart your phone

2. Clear all cache and cookies

3. Enable all background data

4. Update your phone and messenger app

5. Reset all your settings

See also - https://onlinegeeks.net/log-out-of-facebook-messenger-on-android-ios/