Looks like an infinite loop redirect or something. Putting it into compatibility mode only stops the infinite loop thing, but then nothing appears (also looks like the Tracking Protection Lists I have enabled in IE11 are blocking some content). They don't seem to have a working mobile website, but you could try contacting the website owners to check compatibility against IE11. Unfortunately, I can't see a way around this on IE11.
By the way, if you didn't know, MS changed the way Metro apps are closed in 8.1. It's no longer just a swipe-down, as that merely puts it to "sleep." If you really want to close a Metro app, you have to swipe down and hold at the bottom of the screen until the image flips over. Slightly annoying.