cover2 scrollnav issue?

[peiche]

[Submitted on behalf of Michał Matyjasik]

I noticed such an error when I get to the bottom of the post.

Uncaught TypeError: Cannot read property 'id' of undefined https://eichefam.net/wp-content/themes/cover2/dist/js/jquery.scrollnav.min.js?ver=1510864786
    at e (jquery.scrollnav.min.js?ver=1510864786:4)
    at HTMLDocument.<anonymous> (jquery.scrollnav.min.js?ver=1510864786:4)
    at HTMLDocument.dispatch (jquery.js?ver=1.12.4:3)
    at HTMLDocument.r.handle (jquery.js?ver=1.12.4:3)
e @ jquery.scrollnav.min.js?ver=1510864786:4
(anonymous) @ jquery.scrollnav.min.js?ver=1510864786:4
dispatch @ jquery.js?ver=1.12.4:3
r.handle @ jquery.js?ver=1.12.4:3

https://eichefam.net/2017/11/29/you-never-know-how-someone-will-use-your-app/ and scroll down using arrows.

Of course, this error appears when I use Aesop's Timeline or Chapter component