You are right, there is something wrong with Adblock, not Opera. The same problem present in other browsers (Chrome, FF). I have switched to "uBlock" extension which works very good.

One more thing: problem goes away if I logout from my Youtube account. I think that freeze may be caused by loading subscriptions panel on the left. Apparently, Adblock somehow interacts with subscriptions list which leads to freeze.

Yes, if I remove or disable Adblock, Youtube opens without problems.

Now I use my PC at work, and it is also affected by this problem. So, it is present in 3 of 4 computers that I have tested. I have tried to reinstall Adblock, but it didn`t helped.

Hello! Ive encountered the problem: Opera freezes for a few seconds after opening Youtube, and the Task Manager shows that Opera load one of CPU cores completely when freeze happens. Ive figured out that it begins when Adblock or Adblock Plus extension is enabled. My PC is running Opera 28 on Win 8.1 x64. I`ve also tested Youtube on my tablet with Win 8.1 x86 and saw the same problem, but in the notebook with win 8.1 x64 it works fine. Does someone saw this problem too?

Here is the comparison between 27 and 28: http://sta.sh/01d85223xp9e
Even when the "Experimental start page" is enabled in opera://flags/, it looks almost identical to the usual startpage in the new version. I cannot understand why developers have ruined this awesome looking feature. I use Opera browser on my Asus Vivotab Note 8 tablet, and I can say that the previous version definitely looked much better because I was able to quickly identify all sites icons, and it required less space on a little screen. Have you tried to distinguish what site is represented by some small page screenshot consider that the screen diagonal is 8 inches, and its resolution is 1280x800? It is very hard and painful for eyes. Please make the experimental start page look as it were in 27 version. I would really appreciate this.

Hello! Open "opera://flags/" page, scroll down to "Experimental start page" feature and enable it. After restarting Opera new style speed dial will be activated.

Thank you very much, it works.

After updating to v27 my express panel switched back to the old style (with small webpages screenshots). I don`t know how to enable new style. I think new style looks much better because it uses easily recognizable icons.

Похоже, разрабы совсем не торопятся возвращать былой функционал. Почти год прошёл с момента "обновления", могли бы синхронизацию наладить. Или совсем бы тогда убрали из меню пункт "Синхронизация", а то получается издевательство над пользователями. Я не сразу понял, что видео с инструкцией больше не актуально.