More and more users are seeing that the programs ad blockers are not allowed in a message that YouTube displays when they try to watch one video.
It's a constant battle between content creators, Google, and the ad-hating public. Every time Google makes a change that blocks video, new fixes come out that bypass the company's bans.
If usesIn Firefox you can try the open source YT Siphon extension to watch YouTube videos without ads.
All you have to do is tap two keys on the keyboard to play the video in a third-party frontend in the browser.
So you can download YT Siphon from the official Mozilla add-on repository. If you want more information you can see the project repository on GitHub.
This extension adds two actions to YouTube. The first loads the open YouTube video in a third-party frontend when you run the Alt-J shortcut.
The second option adds Shift-click on YouTube to load any selected video in the configured frontend.
The default frontend is at https://piped.video/, but this can be changed in the preferences. The Piped is a privacy-friendly open source YouTube environment. It has no ads, does not track users and does not connect to Google servers.
The service offers many additional features such as audio only playback, SponsorBlock support or 4K support.
I'm using firefox and have uBlock Origin and AdBlocker Ultimate enabled. Both of these disable Youtube's warning that adblocker is present and I have to disable it to watch the video. I found that if I log out of my Youtube account with them enabled two adblockers that I mentioned, then I can watch the videos normally. I personally don't mind not being connected to Youtube in order to be able to watch the videos. I don't know how long this will last, but for now this method works fine. I hope i helped
Chrome with Undetectable Adblocker works perfectly.