Issue when scrolling

Hello! I'm having problems with the "on scroll" animation. I get this error on JavaScript console:

Uncaught TypeError: Failed to execute 'getComputedStyle' on 'Window': parameter 1 is not of type 'Element'.
    at RevealFx._layout (main.js:80)
    at RevealFx._init (main.js:73)
    at new RevealFx (main.js:39)

Any ideas?