I'm getting "200" type responses from their web server so it's sending and gives a valid GetCapabilities document.
But it looks like GetMap requests are sending nothing (ie, a blank image or no results to return for the bounding box requested). This is also seen when loading that layer into ArcGIS Online.
To me, what this suggests is that they have a WFS/WMS server running, but that server can't find data on their end (ie, maybe data changed location on the servers hard disk or they have some funky url rewriting going on - could be a simple fix, but they need to be made aware).
I would let the data maintainer know of this issue so it can be looked in to.