Thanks for reporting this, though I believe something else is blocking that. We rely on the WordPress ajax handler (admin-ajax.php) to do things like start scans. Blocking it would be highly counter productive. It might be another plugin or could be if you meant to block /wp-admin (the URL) and blocked /wp-admin (the folder) inadvertently. Check your .htaccess file in the root of the WordPress installation or in the /wp-admin folder.
Lastly, if you need support, the reviews section is not the place to get it. As a Premium user you have access to our Premium support system at https://support.wordfence.com.
Tim
