@YouTube changed their terms of service and now I can't log in at all despite being a Youtube Premium user? This doesn't seem right, I'm paying for a Service I can't use?
Definitely not the experience we want you to have! Just to confirm, is this happening across all devices? If you haven't already, try clearing your app's cache and cookies with these steps: https://yt.be/help/Cko1 . If that still doesn't help, send us a screenshot of the error.