How to fix a missing Admin Toolbar at the top of a WordPress page

Working on an a client's WordPress site recently, and one of the tasks was to fix the missing Admin Toolbar.  

The client had customised the theme and we could confirm the issue was theme related because if we temporarily changed the theme the missing admin toolbar would reappear 

If this happens to you, the solution is easy enough:

• backup your site
• SFTP to wp-content/themes/your-theme
• locate footer.php
• add <?php wp_footer(); ?> before the closing </body> tag
• save your changes and check your site, with luck you will have fixed your problem