Why are Facebook notifications not showing up in Notification Center?

Question

On OS X Mavericks 10.9.3 Facebook account is setup in Internet Accounts preference pane in System Preferences.
Facebook is configured in Notifications preference pane in System Preferences.
The Share Buttons widget is configured in Notifications preference pane in System Preferences.
When I view my Facebook account via my web browser I usually have notifications available, but these notifications are not showing up in Notification Center.
I do receive Calendar, Mail, etc. notifications in Notification Center so I know it works.
I can send posts to Facebook via the Share Buttons widget in Notification Center, but presently I can receive nothing from Facebook..
Anyone know of a solution to this problem?
Thanks!  
P.S. I read in another thread how Facebook can be setup in iMessage, but I don't want to use iMessage if I can get Notification Center to function properly.

Answer 1

I got it to work yesterday. I tried none of the advice from discussions dealing with changing settings, enabling/disabling accounts, terminal commands, etc. All I did was ask a Facebook friend to respond to a post, and I was able to see the notifications in Notification Center.
I know most have their settings configured correctly in System Preferences, but this is how my preferences are configured on OS X Mavericks 10.9.3:
(1) Internet Accounts preference pane:
There isn't much to configure here. I signed into my Facebook account. I checked or unchecked the Calendar and Contacts selections. It doesn't matter. I left the Description, found in the Details button window, as Facebook, but it doesn't matter, either.
(2) Notifications preference pane:
Facebook alert style is set to Banners, but Alerts will also work just fine. This setting is crucial because if it's set to None, no alerts will be received. I left Show notifications on lock screen unchecked, but it doesn't matter if I check it or not. And I put a check mark in Show in Notification Center, and the number of Recent Items can be set to whatever available setting desired, mine is set to 20 Recent Items.
(3) Notifications preference pane:
I placed a check mark on Show share button notifications in Notification Center, which is found when Share Button is selected in the list of notifications like Facebook, Calendar, Mail etc.
Again, I did nothing else, and it just works. As a side note: before I got it to work I called AppleCare and a senior advisor spent considerable time with me trying to find out why it wasn't working. And his last bit of advice was that I should reinstall the OS. He needs retraining because that bit of advice was ill-advised, to say the least.
I simply had no experience with receiving Facebook notifications in Notification Center 'on OS X', and the AppleCare employees had no training in this area, but if Notification Center is part of OS X, and Facebook notifications are part of Notification Center training in this area should be standard, but the AppleCare employees were guessing, not advising, which certainly is not technical support. Hence, my AppleCare dollars were not at work as expected.
So without prior knowledge as to how the specifics of 'Facebook' notifications worked in Notification Center on OS X, my assumption was I would be notified each time someone tagged me, someone liked a comment, post or photo of mine, someone commented on one of my posts, or someone sent me a direct message.
When I asked one of my Facebook friends to help me test it out, the following occurred (I don't remember if I had Safari up and running at this time - Note: I was signed into Facebook via Safari. I say this because AppleCare employees did explain on OS X some applications must be launched in order to received notifications, which in my mind is wasted time and code for Apple developers. Why offer notifications if the application is already launched? Ridiculous, if you ask me. That's what configuring each applications preference to set badge app icons, if it's not already coded by default.):
(1) I sent a Facebook post via Notification Center using the Facebook Share Button.
(2) I communicated with one of my Facebook friends by private message via iOS device and asked for a response to the post I sent.
(3) My Facebook friend responded to my private message, but I don't remember if I received a notification in Notification Center.
(4) My Facebook friend liked my post, shared my post, and commented on my post. I received two separate notifications in Notification Center on OS X, yet I received notifications on Facebook for all three actions, seen via iOS device. By the way, I wish Notification Center notifications would stay in Notification Center until we manually remove them. If they did stay until we manually remove them I would have time to find out which action of my friend I was received the notification for in Notification Center.
That's it!