Solution for Shortcodes in Custom Restrict Content message Version > 2.8.x

For anyone who is currently looking for a way to use shortcodes in the global message for limited access:

remove_filter('the_content', array(UM()->access(), 'filter_restricted_post_content'), 999999, 1);

add_filter('the_content', function($content) {

    if (current_user_can('administrator')) {

        return $content;

    }

    $id = get_the_ID();

    if (!$id || is_admin()){

        return $content;

    }

    $ignore = apply_filters('um_ignore_restricted_content', false, $id);

    if ($ignore) {

        return $content;

    }

    if (UM()->access()->is_restricted($id)) {

        $restriction = UM()->access()->get_post_privacy_settings($id);

        if (!isset( $restriction['_um_restrict_by_custom_message'] ) || '0' == $restriction['_um_restrict_by_custom_message']) {

            $content = stripslashes( UM()->options()->get('restricted_access_message'));

        } elseif ('1' == $restriction['_um_restrict_by_custom_message']) {

            $content = ! empty($restriction['_um_restrict_custom_message']) ? stripslashes($restriction['_um_restrict_custom_message']) : '';

        }

        return apply_shortcodes($content);

    }

    return $content;

}, 999999, 1);