how can i make black arrow work for other units than the dark ranger

i have created a custom version of black arrow that i have given to the green dragons but, something goes wrong and units is therefore unaffected by the buffs. what am i doing wrong?

Buffing arrow abilities only work with a certain set of Weapon Types (in the unit editor, Combat - Attack 1 - Weapon Type): Normal, Instant, Missile, Missile (Bounce) and Missile (Line). This means that you can't have a buffing arrow ability work with a unit that deals splash damage.

changing it from missile splash to just missile did the trick so now it works.