Module Does Not Work At All

I have multiple sites with differing themes, all running on Drupal 7.

I have installed all the required modules per the instructions, and I have attempted to change the global settings and also create specific node settings for custom page titles and meta tag descriptions.

None of the changes actually take place on the sites. They do not show up in the page source code either.

I am using the Danland and Jackson themes, and I am not using the Display Suite. One site uses a custom page.template.php, but others do not.

What am I missing? Why does this module not work at all on multiple sites with differing themes and configurations?

I have done minimal custom coding for these sites, and I largely run Drupal and my modules "out of the box".

This is a critical problem, because there is no way to conduct SEO without a working module. I do not have the coding expertise to build my own solution, and I desperately need to optimize these sites.