Are you talking about the information site or the Active registration page? Active has been giving me problems all day so they seem to be having a problem but I have been able to get to the Disney pages without a problem.
If you are blocking Flash (which I do) you will have to whitelist go.com, wdpromedia.com, and yahooapis.com
ETA: OK, it looks like there might be a link error on the site. When I tried to link to the information page from the root of event overview menu I do get a blank page. If you click on event overview and expand it and select half marathon below the page loads correctly. The same goes for registration. If you expand the registration menu and click on the link the Active page loads correctly.
Active is still having some problems with their search feature which might be causing some problems with their link through from Disney Endurance but the method I mentioned above seems to be working.