Hey guys! I had the same problem. It looks like facebook completely changed the feed url. Here’s what I did to fix it:
First you need to find your new RSS feed link. (It says how here: https://www.facebook.com/help/212445198787494/ but I was having trouble so I just logged in and went directly to https://www.facebook.com/notifications to find my link).
There’s no easy way to add the link changes without going into the code, but it’s such a simple plugin, even a non-programmer should be able to fix it…open up fbf_facebook_page_feed.php (use notepad if you don’t have a programming environment), and go to around line 50 where it has
$feed_link_array .= ',https://www.facebook.com/feeds/page.php?id='.$feed_link_id.'&format=rss20';
and change it to:
https://www.facebook.com/feeds/notifications.php?id='.$feed_link_id.'&viewer=xxxxxxxxx&key=xxxxxxxxx&format=rss20
where the x’s are your viewer number and key number.
Eventually the plugin will have to be updated to include a way to enter the viewer number and key number. But hardcoding it will work for now.
I hope that helps!