How to Add Double Carousel to a Page
The Double Carousel which come with Eram theme is a somehow special element that needs your page to be set in a certain way:
Use it in a Blank Page Layout
Make the containing row stretch and the contents
Add your the Double Carousel element
Then you can add it to the page. Please note that there is an element as the container with the general settings for the carousel and then each slide should be one separate element with setting for that slide.