Arcade missions won't load/ show properly, but rank, prestige, and expansion ones are okay and playable.
http://cloud-2.steampowered.com/ugc/540679788065830437/2FB69C683329C3AD6...
http://cloud.steampowered.com/ugc/540679788065832742/BC83802F4C4F5978CAF...
It said there was a problem detected with my knight and to try restarting. I did that both by logging off/ quitting/ rebooting the Steam client. Didn't help. "If problem persists, contact a GM."
Its same for everyone, or atleast for alot people. live few days without arcade until it gets fixed.