Invitation link takes me to 'Unauthorized'

I just sent out invitations for a game I'm setting up. I sent an invitation to myself, on another e-mail account, so I would know what my players will be seeing, and thus what other info I may need to send them from outside the Roll20 interface... When I clicked on the link, I was (stupidly) still logged in -- so it handled the request as if I was just going to the same campaign page that I sent the invites from. I then logged out and tried again... Whereupon it took me to a page that just said "Unauthorized". Whats up with that?

I suppose that's because you need to be logged as "someone". By logging out you were no more logged as the GM. But you still need to log as a player to be able to play. Just a guess.

Hmm. But if this is the link my players will be using to find the site and the game, and the result they get is similar or identical, it's not helpful in the least. The term "user UNfriendly" springs to mind...