Force of Nature doesn't work on my map

I have a custom ability based on Force of Nature. It seems that unless my heroes are standing with their nose in the trees I get an error "Must Target a Tree" when I try casting it, as if it doesn't know the trees are there. The only thing customized about the ability is the mana cost, cooldown and duration, and the Treants themselves have been modified. None of that should change it's behaviour so maybe I have screwed up some map setting or gameplay constant? I have no idea. Like I said, it does work when the hero is standing really close to the trees.

Thats cause you have tocast it near the trees unless you want to trigger it.

-Av3n

You've probably stuffed up the casting range, are trees within the AoE of the spell when you attempt to cast it?

When you cast the spell, do you have the AOE "circle" dealio replace your pointer, which you then use to target a group of trees, or must you be targeting your hero?

In the first case, you're screwed, I have no idea at all whats wrong. In the second case, as has been previously mentioned, you probably have reduced your casting range of the spell to a very very low number resulting the the AOE targeting circle only being available when highlighting the hero itself (the origin of the spell) thus resulting in the need for said hero to be next to trees.

Solution: Increase the casting range drastically.

OK, I'm probably just being dumb. I tested the Keeper of the Grove in a regular Warcraft game and I get the same behaviour just not as bad. It seems that you need to have direct line of sight on the trees in order to convert them to Treants. The hero I was having trouble with had line of sight turned down a bit. I think that is causing the issues. I think it is dumb but it looks like it is just the way the spell works.

Well, duh. Can you target death-coil on units you can't see? If the hero cannot see the trees directly he cannot target them: they might not still be there even if they appear under the fog of war.