I had same problem. I've found the solution finaly.
1.Access DevCenter on "Safari".
2.Sign in by your AppleID/PW. I think you cant sign in.
3.Delete saved password in Safari, and Preference / Privacy / enable cookies.
4.If you became to able to Sign in, you can sign in on "Organizer".
I hope my poor English helps Slav and someone has the same Problem.
