I tried to use forage by exiling cards from my graveyard, but it wouldn't let me select cards to exile. So it is not letting me forage that way. I was using Ostemancer Adept from Bloomburrow and tried to use it ability. I have 4 creature cards in my graveyard. I tried to cast 1, and exile the other 3, but when I casted the spell it asked me to select 3 cards to exile, but it wouldn't not let me select them.