WordPress is a great blogging tool and does an adequate job handling comments, but if you want to provide enhanced discussion capability among your sites users, you must install additional software. The WordPress developers have created bbPress to fill this purpose, and in doing so also added the ability to integrate the two tools on one web site. The key components that are integrated include users, cookies, and the back-end database.
Integration the two products was amazing easy – except for three items needed by bbPress installation. bbPress asked for WordPress "auth" cookie salt (AUTH_KEY), WordPress "secure auth" cookie salt (SECURE_AUTH_KEY), and WordPress "logged in" cookie salt (LOGGED_IN_KEY). The scant documentation insisted that these values were located in my wp-config.php file located in the root of my WordPress installation directory. Since my initial WordPress installation was at version 2.6 or so and has been upgraded many times to version 2.91, these values were never added to my wp-config.php file.
My bbPress installation was halted essentially because these values were required to proceed. Fortunately, I found a tool at wordpress.org that generates these values for you: https://api.wordpress.org/secret-key/1.1/. Just use this link, copy the four lines of keys, and paste them into your wp-config.php. Save your updated wp-config.php file, then go back to your bbPress installation page and paste the keys into the appropriate text boxes and the remaining portion of the installation should go smoothly.
More information about this process can be found here.