During the final battle against Cyanigosa, the boss played a secret they got thanks to Shifting Scroll. I played Carnassa’s Brood, which triggered the secret and turned the Brood into a sheep, however the icon of the secret itself did not appear (leaving Shifting Scroll’s icon on the board). I was able to play King Krush, but attacking with him froze him too, and ending my turn didn’t do anything.
After re-launching the game I was met with an empty board (unknown if due to bug or a board clear), and while I was able to beat the boss in the end it almost ruined my run.
I would post a link to an imgur post with screenshots, but I’m not allowed to post links.
There are countless reports of this already. In the adventure, every time a Shifting Scroll morphs into a Secret and is then cast, this will happen when the secret is revealed.
Until Blizzard fixes it, the only solution appears to be a quick force-quit of the game, then restart. After it reconnects you should be able to continue the game.