Two things I noticed: the Find Trains button paused the screen a while but did nothing else so I'm not sure if it worked or not and the London Overground station Bush Hill Park that my ticket went to was not listed so I had to enter the nearest (Enfield Town). I also tried using the intermediate station London Waterloo but got exactly the same message whenI submitted.
I think it's not hard to fix this problem. Read this boom essays review later. It will be good for you.