[theme: Alum] slider, widget, icon

Hello!

Unfortunaltely, I have some troubles with my website. I love the alum theme, but it doesn’t work. Or I don’t. When I add files to the slider via the customizer, the slider doesn’t apear. Also, when I add widgets in the footer it doesn’t show. Also the icons aren’t visible.

Does anyone know how to solve this? I like the theme so much I don’t want to switch to another…