That's why I was so disappointed because to be honest, Vivaldi never really introduced major or annoying bugs until Vivaldi 5.1 and this might turn new users off, so it's really unacceptable. They should strive for a higher quality. But like I said, I wouldn't even care that much if I could simply downgrade to an older version while maintining my settings and extensions. And Vivaldi Sync might help, but I'm not yet ready to use such a cloud based service, especially because I also save passwords inside the browser. And we all know that password managers from browsers aren't that safe, they should really beef things up, I rather see them investing time into this kind of stuff.