Probably all Facebook developers should have aware of the recent service disruption on the Facebook platform for which our developers may be disabled with the apps banned. Facebook should have fixed that in a very short period of time and hopefully the impact is minimized.
There may be another issue that worths to note. If you own any Facebook Canvas application, please check to see if if still works. It is found that some of the namespace field for some of my canvas apps get removed suddenly.
I believe Facebook had recently made the “category” field of the app a mandatory field. And for canvas apps that do not have the category field set, the namespace field was removed.
Go and check your canvas app(s) at https://developers.facebook.com/apps?view=all_apps.