I am probably not the only one with this problem : basic/classic cards seem to have been removed from Hearthspwn deck builder, and it creates a bug when I want to edit my decks. The basic/classic cards disappeared from the decks and, most importantly, I cannot edit anything, it just blocks on a never-ending grey loading screen with Pacman (kinda).
I ended up rebuilding the decks ;/
:)
https://hsreplay.net/replay/27u2NJTZZJgToJ6k6n5BTM