Art overhead of caster

Art overhead of caster

I have ART-Caster exlamation mark ART-Caster attachment point 1 (overhead)ART-Caster attachment point 2 (blank) ART-Caster Attachments 1
but nothing happens, i changed the model file from the original unit (footman) to city building large green and also the pathing map when i made it a building then made it a unit again. Is there a way to make it higher or something to show up when you use an ability?
thx

i think over head is spelled serparate
failing that use special effect trigger