Sounds like UA has a problem with the double connect for some reason or other. It seems about the most direct Star routing to CMB from BSL (another option might be BSL-VIE-SIN on LX/OS). I think that should go to a sup or something. Yes, the milage may be over and it is a fairly long routing, but there aren't any better options that I know of available as a Star award using UA miles - so what do they expect you to do?