As developer has written in recent reviews

"We believe this is an issue related to being unsubscribed to our primary filter list, EasyList. To enable EasyList, please click the AdBlock button in the browser toolbar and select Options. On the Filter lists tab, select "EasyList".

I did exactly as written and it has worked. So I recommend every one who has said issues give this an attempt before totally giving up.

Also, thank you to developer for informing about this.

good

Молодцы; Разрабодчики я очень доволен этим расширением что самое главное в этом расширении не нагружает строницы при загрузки веть в этом и-есть приемущество ещё раз молдцы разрабодчики Респект им и Уважение я буду дальше им пользоватся! Ато надоели всякие расширения перегружают тупят строницы долго ждёшь пока они загрузятся ну тк-далее только не перепихевайти его и не перегружайти за ранее спасибо !!!

Latest version (4.7.1 at the time of this review) came with a small glitch allowing ads, which they quickly addressed, and helped to resolve (on a Saturday, no less)

EDIT: Thank you Devs for your reply. I have tried your solution and it worked, i have also changed the review.

OLD ISSUE: "it had an update and now its not blocking about 90% of ads and popups"

Updated to 4.7, and was horrified at the sight of YouTube ads. :'-/ This won't do, so I reverted to 3.37 and all is well again. :-) I'm on Firefox 72 on W10.

[UPDATE] I followed your instructions below and updated again, and enabled "Easy List". That was the fix. 4.7 is working! Yay!

Thanks for a quick problem solving!