Menu bug: html structure

It is not a question. Your menu looks like:

<ul class="subsubsub">
    <li><a class="" href="https://wordpress/wp-admin/tools.php?page=redirection.php">Редиректы</a></li>
    |
    <li><a class="" href="https://wordpress/wp-admin/tools.php?page=redirection.php&sub=groups">Группы</a></li>
    |
    <li><a class="" href="https://wordpress/wp-admin/tools.php?page=redirection.php&sub=site">Сайт</a></li>
    |
    <li><a class="" href="https://wordpress/wp-admin/tools.php?page=redirection.php&sub=log">Журнал</a></li>
    |
    <li><a class="" href="https://wordpress/wp-admin/tools.php?page=redirection.php&sub=404s">404</a></li>
    |
    <li><a class="" href="https://wordpress/wp-admin/tools.php?page=redirection.php&sub=io">Импорт/Экспорт</a></li>
    |
    <li><a class="current" href="https://wordpress/wp-admin/tools.php?page=redirection.php&sub=options">Опции</a></li>
    |
    <li><a class="" href="https://wordpress/wp-admin/tools.php?page=redirection.php&sub=support">Поддержка</a></li>
</ul>

But it is not allowed in <ul>...</ul> to have something except <li>, <ol> or <ul>. See: https://developer.mozilla.org/de/docs/Web/HTML/Element/ul

I hope, you will fix it and your plugin will produce a valid HTML 😉

Thanks, I will wait for this fix 😉