Log In via Apple Settings > Facebook
To Log In to the ESR app and other apps, using Facebook for authentication, *first* Log in to Apple Settings > Facebook on your device.
Some iPad/iPhone users are experiencing issues logging into their Facebook accounts through the app after upgrading to the new iOS. The Facebook login is entered in the Settings screen. Users suffering from this issue usually get an “Error Signing In Could not communicate with the server” message after typing in their password and are unable to delete the account.
The System pulls the Facebook login data from the previous iOS before you updated, therefore anything you enter in the new iOS’ Facebook setting will not actually be used.
1.) Open Apple Settings
2.) Open the Facebook app
3.) Log In to your Facebook account
Another solution:
Go to Settings > Privacy > Facebook
Disable the option for Facebook and re-enable.
Final solution:
Go to Settings > General > Reset > Reset Location & Privacy
Once reset, login to Facebook via Apple Settings > Facebook