@YouTube your website is constantly signing me out of my account? Why are you treating me like I haven't been a premium member over 5 years? I'm not trying to look at no ads
Let's take a look – are you experiencing the issue whether you log in to a computer or a mobile device? If so, mind sharing a screenshot of the error, if there's any? Otherwise, try clearing your cache and cookies with these steps: https://yt.be/help/Cko1 . Keep us posted!