Missing header sidebar?

Has the header sidebar been removed? There’s a reference to it under the header settings, but there’s no such thing under widgets.

this is no standard beviour, so what theme are you using?

If it’s gone, how can I easily add a space for a banner ad between the header menu and the rest of the template content.

edit the corresponding template file.

Constructor https://code.google.com/p/wp-constructor/
Very nice theme otherwise, very customizable, but it seems like the header sidebar is missing and I’m not really a coder, so no idea how to edit the template file.

details depend on the code of your banner ad, but generally:

edit header.php;
find:

<div id="description"><?php bloginfo('description');?></div>
            </div>
       </div>
   </div>

add a div for your banner add for instance here:

<div id="description"><?php bloginfo('description');?></div>
            </div>
       </div>
<div id="header-banner">YOUR BANNER AD CODE HERE</div>
   </div>

to style it, you can then use
#header-banner { ... }
in style.css

details depend on your setup.

Thanks, will have a look