Hey guys, i created a new theme based on the vanilla theme. 
Everything works fine except the background-images which can be set in the Authoring-Tool.

They just dont appear in the course neither visibly nor in the html-structure.

For example: I create a course using the vanilla theme > Add Background-images (article,page, does not matter) > Preview ----> The background-images are visible.

When i do the same using my own template, the information is not saved and no background image will be visible (the "style="background-image-Tag" is also no added to the html of the output).

When i create a new course, using the vanilla, then add bg-images and then change the themes it works until i open the article/page-settings again. 

The other information beside the background-image-src like the position, the height of the container, all those information are not included in the preview/output 

Do you have any ideas? I reseted my proporties.schema back to the values of the vanilla-theme with no effect. 

I just realized that it is working fine in the course settings and for the menu-page.