I'm having troubles joining Area 51 community.
From here https://area51.stackexchange.com/ if I click on Log in, I'm redirected on a page saying "Completing log in to Area 51, you will be redirected automatically", then I'm redirected on a page saying Unable to log in: user not found.
From here https://area51.meta.stackexchange.com/ when I click the blue "Join this community" button in the header, I have the same behavior as previously described, however if I click the grey "Join this community" button in the... sub-header, I'm redirected to the usual "Confirm your new account" page with the following text: "You are about to create a new account on Area 51 Discussions using a login from Stack Exchange. We will automatically link this account with your accounts on other Stack Exchange sites.", but if I confirm I'm redirected to a "Page not found" page: https://area51.meta.stackexchange.com/users/openidconfirm