It is learnable, just not clickable.
In the alpha, the hero ranger use The Black Arrow as an ultimate ability to paralyze her foes, so they are but one point of their overall health. As an example, it's exactly how Sylvanas paralyzed Arthas before Kel'thuzad saved him.
In the alpha, the hero ranger use The Black Arrow as an ultimate ability to paralyze her foes, so they are but one point of their overall health. As an example, it's exactly how Sylvanas paralyzed Arthas before Kel'thuzad saved him.
Or you mean that when the hero learns it, he cannot cast the ability? In that case it is expected since the base ability is a passive ability.
Passive abilities can never be "clickable" as you say.
So be wary of the base spell you use for custom spells.
What is your end goal with the ability?