Phantom Facebook notification?

[Angel Witch]

I went on Facebook today and it said I had one new notification, but when I clicked the notification icon there was nothing there. Why does this happen? Is it possible that someone liked or commented one of my posts then decided to unlike/delete it, and I still got a notification?

[BenB]

Either someone did something to trigger a notification and then 'undid' this action or you are just experiencing one of Facebooks many notification issues.

Often, especially if you have multiple Facebook windows open, you will get notifications for the same thing pop up more than once, even after checking already. Another thing that can cause this is it you get a notification to your phone and or computer, check it on one device, then go to the next. You will still see the notification but it will appear as though nothing is new.