Clicking "Sign in with Facebook" results in an error

If you get the following error when connecting your FB page:
This means there may be an firewall, proxy or VPN enabled on your computer. Or that the cookies are disabled in your browser.

You'll have to disable these things on your browser and computer. Or you can try connecting to Facebook from a different laptop.

It's best to connect your FB page while using a laptop or desktop (instead of your phone)