Facebook Messenger is an instant messaging application for mobile phones. A Windows and OS X version of the application is in development. Facebook Messenger allows users send and receive text messages, as well as photos or video.
It's possible that too many apps are using push notifications and the Messenger app is not listed in the Notifications & Activities list. There is a limit on the number of apps that can send push notifications. It might be worth removing any other apps you don't use to see if this helps. www.webroot.com/safe
