"No Target" bug

I'm trying to shoot at enemy gangers, with an Autocannon (range 50m). I've a higher elevation than my enemy, and the line of sight is very clear between my target an my ganger. The target is 40m away, and yet, I have "no target". There are three other targets near the first one, every one of them in range too, and none of them attackable. How come ?

Screenshot for your appreciation: Screenshot of the situation

I'd gladly have taken another screenshot to show where I was exactly (on the edge of a catwalk, no handrail or anything to hinder the shoot), but when I tried to cancel the order selection, with a right-click, I got a crash to desktop...
I'll send the relevant crash info, saves, call stack, etc, on the support mail address, as 1.4MB seems too "heavy" to upload here.

Ok, yep, I had gathered as much from other problems. This explains the unability to fire. I'd say we can close this thread, then (however, I still find this game mechanic to be undesirable - and not only because it's poorly (if at all) documented).

I have posted another thread about this, and hope it can be modified - especially if the community feels the same way.