This is the offendig code being replicated. Please note the duplicate id="navbar" and the duplicate </nav> tag.

    <div id="navbar" class="navbar-collapse collapse col-xs-12">
      <ul class="nav navbar-nav">
      </ul>
      <ul class="nav navbar-nav navbar-right">
        {SAVE_LINKS}
        {CLEARALL_LINKS}
        {QUESTION_INDEX_MENU}
      </ul>
    </div><!--/.nav-collapse -->
  </div>
</nav>