I could open the MHTML and see the page opened. But it behaves strange. I can not, even manually, scroll the page down at all. I do not see why. I looked at the HTML source of your page, found it is very much sophisticated (complex, complicated, …). I guess, the javascript in the page is AJAX-driven, requires a live continuous connection to the backend server, so that the page frozen in a MHTML does not act properly.
I am afraid I would not be able to dig into your problem with a dead MHTML.