[Captain_Insano]

I didn't look at your attachment but I'd bet you an 88 it has something to do with chain of command. Either your mortars are out of contact due to spotty radio communications or you are trying to order their fire from a unit that is not thier company commander or higher.

As an aside one thing to watch out for is if you plot some fire when your mortars are in contact and then move some of your own infantry in to the fire zone later hoping to redirect or cancel the fire mission - if your mortars have lost contact in the mean time they will still fire as ordered because they can't get the message to stop - quite tragic.