ACF – ADDING IN MU-PLUGINS OR 3RD PARTY PLUGINS Posted on September 1, 2020 by CG Team I have recently moved ACF into mu-plugins on a rather high-traffic site. I’ll let you know about the problems as they arise. I simply put the advanced-custom-fields-pro directory into the wp-content/mu-plugins directory and added this modest file to that directory as well: $ cat advanced-custom-fields-pro.php <?php require_once(__DIR__ . '/advanced-custom-fields-pro/acf.php'); The site in question does not need the update mechanism in place as we update the code on another machine, commit to git, and then deploy on the production web server.