POP UP - TypeError: Cannot read property 'top' of undefined

Hi

I have Chrome 50.0.2661.94 m and when I use POP UP plugin, the console show me an error message if I scrolling on the page.
public.min.js:4 Uncaught TypeError: Cannot read property 'top' of undefined

However I use this lightweight and nice smooth scroll plugin:
https://wordpress.org/plugins/smooth-scroll/

Can you solve this?

http://footballheroes.corewebstudio.net/ - live preview

Best regards
Peter