Could not use Dauthi Voidwalker's [MH2] activated ability to cast a card from exile.


Here my opponent has an Orchard Strider exiled with a void counter on it. [[Dauthi Voidwalker]] has the activated ability, "{T}, Sacrifice Dauthi Voidwalker: Choose an exiled card an opponent owns with a void counter on it. You may play it this turn without paying its mana cost." Despite Dauthi Voidwalker being highlighted clicking on it did not allow me to activate this ability.