Facebook do this now and then unfortunately and you may need to reset it.
Please log into FAA and disable both FAA apps
Then, remove the app from your Facebook Pages
FACEBOOK PROFILE
Go to your main homepage and see APPS on the left menu.
Delete the FINE ART AMERICA APP
FACEBOOK PAGE
On your FACEBOOK page, go to EDIT PAGE
On the edit page see the tab for APPS
Delete the FINE ART AMERICA APP
YOUR SITE HERE
Then, Make sure you are logged into Facebook as you, not as your page, and come back to your BEHIND THE SCENES | Facebook Application and enable the application again, Middle one (FB personal profile) and then the right one (FB page) If it does not popup, use a different browser and make sure your popup blocker is not enabled, or any ad blockers
The profile side must be enabled as well as the page but, you may turn off postings to that page in your default settings, once the application is all working
Then contact me if you only have a number in the Facebook shop
Don't worry... it will work but sometimes they need a virtual kick.
