There was a mishap on the last update regarding the signup process on the site that affects users that authenticate using their Reddit accounts.
Reddit does not provide third party sites the email address the user has on file. I think this is a fine security policy. The problem is that in the old signup flow we'd always ask users for an email address. In the new update since most authentications providers would give an email address we opted to remove that screen completely forgetting about Reddit.
So, since then on, all users that sign in using Reddit will get their emails blanked. I have restored many from backups, but users who have created their accounts with Reddit never had an email on file. So I cannot recover those.
You will see on the top of the site a big red warning telling you that you need to set up an email address. You just need to provide one and we'll be on our way.