Problem with I18N navigation menu

[BF68]

Hi There,

Just started with GetSimple which I wnat to use to rebase my private website. My current private website at www.lieberlinge.de is completely handmade and somewhat outdated.
The goals of rebasing it on a CMS like GetSimple are:

• Make it easier to change the look and feel
  
• Allow my wife without html knowledge to update the site
  
• Get a more modern look and feel
  

One of my key requirements for the new site is a multilevel navigation bar and when I checked the options with GetSimple a couple of months ago I didn't discover I18N. Now with I18N it should be possible in a simple way to get such a left-side navigation menu.

However I struggle to get it to work. I have built the following pages:

20170205_Screenshot1 by Bernie None, auf Flickr

I use the theme "ThemeSettingsDemo" and in it's default template.php I have the following mostly unchanged section:

PHP Code:

   <div id="main">
        <div id="navigation">
            <ul><?php get_i18n_navigation(return_page_slug(), 0, 100, I18N_SHOW_MENU); ?></ul>
        </div>
    </div> 


But if I call the site it shows the following
20170205_Screenshot2 by Bernie None, auf Flickr

Where I miss in the red circle the expected navigation menu.

Anyone any idea how to fix the issue?

Many thanks in advance!

Bernhard