windows velux

hi everyone, i have this velux ghl 304 roller shutter which it's stuck, it doesn't move at all. when i try to raise it, it just make a clicky sound. do you know where the problem is located? if you have any advice on how to fix it please tell me. Thanks

I've inherited a large velux window and I'm wondering whether it is possible to use them in vertical walls, instead of a "normal" window? I can't see a reason not to, but I'm probably overlooking something really obvious... Any help greatly appreciated.