Hi,

If you are using a mobile device, we are currently unable to consistently block ads on YouTube.

If you are using the Adblock Plus extension on a desktop browser, you should not be seeing full length ads though you may see a variety of different behaviors such as a temporary black screen or a very brief display of an ad (less than a second or two). These are related to our efforts to stop the entirety of the ad appearing.

If you are seeing full length ads, I recommend checking out this article: https://help.adblockplus.org/hc/en-us/articles/26653087560595-Ads-appearing-on-YouTube

If the steps in that article don't help, could you send us a message to support@adblockplus.org ? We will be happy to look into it!