I too am having difficulty getting past the login screen. I've been able to login every day this week and then always get the message that there are no fastpasses available for our date (March 15th). But now today I get this weird error saying "Thank you for participating. Please try again later. If you continue to encounter this message, you can seek further assistance at the Lobby Concierge desk at your Walt Disney World resort or upon arrival at the Be Our Guest restaurant". Not sure what is up with that since I haven't participated yet. Argh. Hopefully it'll be back to normal tomorrow.