Uncaught TypeError: popper is null

zoidts

I am working locally with XAMPP as I am making some modifications for a category menu. The problem is that some categories have subcategories and I started redesigning the menu by overriding module_menu. The problem is that when working I get the following message "Uncaught TypeError: popper is null" How can I solve this error?

saguaros

Hi zoidts

It seems to be JS error, you can put your site online and share the detailed login info so I can help.