dokuwiki/conf/plugins.required.php

<?php
/**
 * This file configures the enabled/disabled status of plugins, which are also protected
 * from changes by the extention manager. These settings will override any local settings.
 * It is not recommended to change this file, as it is overwritten on DokuWiki upgrades.
 */
$plugins['acl']         = 1;
$plugins['plugin']      = 1;
$plugins['config']      = 1;
$plugins['usermanager'] = 1;
$plugins['revert']      = 1;