Install theme required plugins
When you first install the DirectoryStack premium WordPress theme, you will be prompted to install the required plugins, you'll see a message very similar to this:
Once you click the link, you'll be redirected to a page with the full list of required and recommended plugins. The listed plugins are needed so that the theme can correctly function.
Alternatively you may access the required plugins page by navigating to Appearance → Install plugins in your WordPress admin panel.