How to fix reCAPTCHA 'Cannot read property 'closest' of null' issue?

Question

reCAPTCHA

Hello, when loading reCAPTCHA on a page, 2 errors pop up in the browser console (Opera 49.0):
Uncaught TypeError: Cannot read property 'closest' of null at HTMLDocument.document.addEventListener (browser.js:277)
Code on line 277: The site is running on localhost, and written from scratch. How can you overcome mistakes?
let toHide = el.closest('div[role="dialog"]')

Answer 1

I have exactly the same problem, and this is only observed in Opera.