To encounter this bug, I just entered the deck builder. Any limited event and the collection deck builder all produce the same issue. I tried this on PC Steam and PC standalone install. When entering deck builder I just get an endless loading screen. I am unable to edit my decks. This error doesn't happen on another computer in the same local network, however reinstalling the game did not help on my PC. I tried port forwarding ports 30010, 30003, and flushing DNS cache, as well as trying alternate DNS servers. I also tried a clean reinstall using Revo uninstaller. I am on a wi-fi connection by the way.