Hi Juan Pérez,
I just tried with the lastest adapt framework and added the Carrousel menu into the framework by going to the "adapt_framework/src/menu" folder and removed the "box-menu" folder and added the "adapt-carousel-menu-master" folder unzipped in its place.
I then went to the "adapt_framework\src\course\en\contentObjects.json" file and copied and pasted an image link into the "co-10" "_graphic" "src" spot. I then did a "grunt build" and "grunt server" and it worked like a charm. I attached a screenshot.
Here is the latest version of the adapt-carousel-menu, looks like you have an old one which could be the problem too as the left and right arrows are now obsolete...
https://github.com/mike-st/adapt-carousel-menu
*Make sure to empty your browser cache incase that is the issue otherwise try these steps again from scratch with the latest adapt framework.