Not working still getting ads

I'm using the latest Firefox version. This add-on DOES NOT block the preloaded ads that start before the actual video.

Edit: Thanks for your reply. I've changed the settings as required but ads are still popping up for a few seconds whenever I move the slider during video playback and than the video gets stuck.
In the meantime I've found another add-on that does the job better.

Amazing! Does what Adblock+ can no longer do, block ads on youtube!
Seems to "catch" the ads as they attempt to load and somehow gets it to immiediately stop.
Would this count as ad viewed on youtubes side? Idk.. but i no longer get the black screen saying "no adblocking, you can not play the video until your adblock is off", so it's definitely making youtube think it's winning.