Footer disappeared

For the website https://www.gympower.org/nl/ we use the Sahifa theme. We use a picture as background, behind the widgets there is a light colored background (<div id=”main-content” class=”container”>)
Since a few days we have a problem with the light colored background and footer of the page. The background is about 30 px high and only visible behind the breadcrumb. The footer isn’t shown at all.
The footer has to be in the wrapper… but how can we manage that?