Big Bad Evil Voodoo problem

[Billy the Cat]

For my map I have been trying to make a spell that uses Big Bad Voodoo, but when I make Big Bad Voodoo a unit ability and make a unit use it all units near that unit go:
Invulnerable
Not invulnerable
Invulnerable
Not invulnerable
Invulnerable
Not invulnerable
And so on...
Every second.
When I give it to a building, only units nearby the user (nearby meaning: standing right next to it, and that's for about 100 range) get invulnerable even when the the area of effect is put on 9999999999.

Anybody knows the problem or is it a weird spell?

 

[ap0calypse]

For the unit:
I just made it a unit-ability and it worked, I don't know what can be the problem :s
(these were the settings:
cd = 0
duration = 10 - hero and unit
Mana cost = 0
Targets allowed is default + mechanical, organic
AoE = 500)

For the Building:
Set cast range = the AoE you want
AoE doesn't matter in this case, Cast range does

You don't want to know how long I've been searching for the building xD
This just isn't logical, but it works

 

[Billy the Cat]

Ok will try that. I guess I had my targets wrong for the unit problem.

Edit: Doesn't make sense , but it works so I guess this problem is solved

+rep for helping me out and thanks!

- PROBLEM SOLVED

 

[ap0calypse]

Yeah... it's like you said: it's just a weird spell
First time I've seen anything like that though :/

and you're welcome ^^