What you were expecting to happen, and what actually happened:
Last troop was cursed, lycantrophy active, burning, stunned, entangled, frozen etc. I cast Queen Ash and killed troop above, nearly killed final troop.
Final troop changed into Festival Cow and locked - similar to previous 8.2 bug fixed in 8.3, no moves possible, is opponent’s turn…
Also, Queen Ash is still bugged, there was a response that it was going to be fixed (2 years ago?) so that it doesn’t fire at nothing when next to last target is killed or opponents are in first slot or 4th,
Furthermore, heroic gems like freeze gems and curse gems are still problematic, at least twice last week I got Cliffy Errors and game crashed. Happens when heroic gems on board.
How often does this happen? When did it begin happening?
First time since 8.3 update.
Steps to make it happen again
I’m guessing some combination of heroic gems, status effects and lycantrophy/summoning.
This seems to be a different type of issue. Do you happen to remember what that last troop was prior to transforming? Back when lycanthropy gems got introduced there used to be a bug with the hero transforming, maybe this somehow got patched in again.