iOS Facebook: Error signing in. Could not communicate with the server, fix

Several users have reported issues logging in to Facebook. Users are receiving the following error message:

Error signing in. Could not communicate with the server

If you’re experiencing issues when you try to use the Facebook app for the iPhone and the iPad (e.g. If you’re having trouble logging into your account with your Facebook username and password), try the following fixes:

• First make sure that your username and password is correct. Try signing in to facebook.com via Safari. If you’re still having trouble logging into your account, you may want to reset your password by going to https://www.facebook.com/recover/initiate
• If you have no trouble logging in via Safari, try closing your Facebook app and restart again. To do so, double press your home button and swipe upwards on the Facebook thumbnail. The reopen your Facebook and try again.
• If you are still having problems, restart your iPad or iPhone. If restarting does not fix your issue, reset your device by pressing and holding the sleep/wake and the home button together until you see the Apple logo.
• Tap Settings > Privacy > Facebook and toggle off the Facebook option. The open your Facebook app, try to login. After you login, go back to your privacy setting and turn the Facebook adoption back on.

More: Facebook push notifications not working; fix