Category widget not working

Hi,

I’m using expo theme and wpdm, everything seems fine except the category widget, when i click any from the category, it will only display/open a blank slider/block. Anyone have idea why?

Here’s the website wpdm/

I’m planning to use the pro but before that i want to explore since i will be using this for client.

Thank you in advance,

https://wordpress.org/plugins/download-manager/