Pulldown menu does not work for subtheme

Created a new subtheme based on the LESS starterkit. Created few menu entries and submenus under "Main Navigation". For menu entries with submenus, selected "Show as expanded" for parent menu entry. The caret appears showing that there are submenu items for the menu entry, but on clicking the parent menu item nothing happens.

Tried the same with bootstrap base theme without changing any other configuration and now the dropdown menu works.

Generated HTML for both base theme and subtheme looks the same, below is an example for one of the menu entry with submenu.

<ul class="menu nav navbar-nav">
    <li> <a href="{link}" data-drupal-link-system-path="node/1">{Parent Manu-1}</a> </li>
    <li class="expanded dropdown"> <a href="{link}" class="dropdown-toggle" data-target="#" data-toggle="dropdown">{Parent Menu-2}<span class="caret"></span></a>
        <ul class="menu dropdown-menu">
            <li> <a href="{link}" data-drupal-link-system-path="{path}">{Sub Menu}</a> </li>
        </ul>
    </li>
....
</ul>