Esssential grip and one.com performance cache

I get error: Uncaught SyntaxError: invalid assignment left-hand side and grid doesn’t appear
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Errors/Invalid_assignment_left-hand_side?utm_source=mozilla&utm_medium=firefox-console-errors&utm_campaign=default

The page I need help with: [log in to see the link]