Trying to check in for an international itinerary starting in HKG on the iPhone app. First attempt took forever and then said "the app is having difficulties, please try again." Second attempt was quicker but same result. Third attempt said, "you could not be checked in, please do so at airport."

Not that I mind much because I can check in at the HKG Airport Express station which is fast and awesome. Just wondering what the problem might be.