In the game #4391 on frankfurt-test2, I played a wishing well and when the scrying pool pile was empty I could not choose the scrying pool pile. Turn 16 and 17 it was not a problem because I can choose the scrying pool in my hand, but turn 18 no scrying pool in hand. So I can't wish for a scrying pool.
It is the same with Mystic. I can't name a card not visible (for example in game #592 Encampment) or a card from an empty pile.
I ran into this issue today, bumping this.
Different but related...
When i make a wish, i only find out if I got my wish by looking at the log. Can you show the card revealed?
I have not seen it fixed in release notes, but it works now. I can name a card from an empty pile.
Still it is not possible to name other cards like Hovel not in your hand.
the issue only occurs if you reloaded/undid during the game.