Facebook is currently updating it’s API, you don’t need to worry but please be aware there may be some connectivity issues with Facebook features while this is updated.
Note: new facebook API will not work until review and changes are done, you can read the link below: https://developers.facebook.com/status/issues/205942813488872/
What have we done?
We have fixed Facebook Login with new API enforcement rules for HTTPS. And added the correct redirect URIs in the Editor > Settings > APIs page. Push notifications with Facebook users has been fixed, and Facebook import has also been improved.