UPDATE as of 06/15/2016
We're happy to inform you that the issue is now fixed! You should be able to connect to Facebook as usual and get back to playing the game. Please force-close the app to see the fix.
END of UPDATE
We are receiving reports that players are having issues connecting their game to Facebook using Windows Platform (PC and windows mobile). We are already working on a fix for this.
Stay tuned for updates as we will have you notified once we have this sorted.