Safari OS X: Fix Facebook web login buttons not working anymore

Here's a fix for Safari 8 on OS X Yosemite on how-to resolve the issues with the Facebook Single-Sign-On Login Buttons on websites not working anymore, due to a strict Cookie & website data restriction setting in Safari's Preferences.

How to Fix “Safari Can't Establish a Secure Connection” Error

Safari (web browser) - Wikipedia

How to Manage Pop-Up Windows in Safari on macOS Monterey

Make older Macs feel new again by switching web browsers [Pro tip]

Fix: Safari Private Browsing Greyed Out in Safari on iPhone, iPad - The Mac Observer

Remove Safari virus warning from Mac/iPhone - MacSecurity

How to Put Safari's Search Bar Back on Top in iOS 16

How to change your Safari Homepage on Mac, iPhone and iPad

Safari OS X: Fix Facebook web login buttons not working anymore – Swiss Mac User 

Safari OS X: Fix Facebook web login buttons not working anymore – Swiss Mac User 

Solved] Assistantd Wants to Use Login Keychain on Mac

Tab key is not working on Mac Safari – CORE Help Center

How To Reset Your Safari Web Browser – Intego Support