I can login to my Yahoo account but not Yahoo mail

Hello,
I recovered Yahoo account and tried to change my login / primary email address. I found instructions to do that in mail settings. But I can not get in to mail. It keeps warning:

Setting up your mailbox
We´re in the process of setting up your mailbox, which can take a few seconds.

And then there is Try again button.

I have waited and tryed again, nothing.