Ability won't add damage

I have an ability based off flaming arrow and it won't add damage when auto casted. Anyone know what's wrong?

Is it a melee-range ability? I've had difficulty making it work at close distance.

Also, Searing Arrows counts as an orb-style ability, so it won't stack effects with other orb-based abilities or "arrows", but it will stack damage.

It's not a close range ability and I have no other orb abilities. My unit has a bash based ability, a bear form ability and a searing arrows ability. When it's auto casted it's take up mana but doesn't add damage when he shoots...

I've had that problem before. It sounds like an orb is affecting it or it could be that you changed the icon. I've had problems with that too.