Pay attention. After the last browser update, the "Adblock plus" and "malwarebytes guard" extensions suspend the YouTube tabs that open, which is why you have to restart your computer.

Encountered it after the last update. When opening a new tab with a video on YouTube, a message appears that "Adblock plus" and "malwarebytes guard" slow down the browser, while the tab freezes, and even after closing it, it is impossible to open a new tab with a video (empty tabs open). Restarting the browser does not help, only restarting the computer. At the same time, I want to note that I am in Russia, where YouTube is launched only when VPN and similar means of circumventing locks are enabled (I use zapret).