I clicked on the link on my invite e-mail, but didn’t download or link the invite to my github account or anything like that.
Since then, I’m able to log in to the atom.io page using the Sign In link at the bottom, but nothing related to download appears.
I have looked at the pinned topic and don’t think my case is described there, since I received my invite, but didn’t confirm it.
I can’t even send invites to other people, visiting /invite gives me a “Whoops! It looks like you don’t have any invites.” message.