Hey there!
Sam from Moz's Help Team here!
I've taken a look at that URL, and from what I can see it looks like we're running into a 403 error which means that ultimately, access to that URL is forbidden:
http://www.screencast.com/t/UbMwIrjuQFG
This 403 error is coming directly from your server, so at this point the best thing to do will be to send this information to your client/their web dev. They'll need to make sure our crawler (rogerbot) is whitelisted, so our tools can start working hard for you, and that you aren't blocking AWS (Amazon Web Services) on the server level.
I hope this helps - if you have any other questions, feel free to pop a message over to [email protected]