I'm using Ammyy Admin. I've set all permisions. However once connected I receive "Remote desktop is unavailable" message. Why and how to fix this?

upd if I have windows rdp connected then I'm able to use ammyy admin rdp. But once i disconnect windows rdp, ammyy admin rdp is also disconnected. This is strange and makes ammyy admin useless (in my configuration). I need ammyy admin rdp to work even if windows rdp is not connected.