Just last week I was able to create a new map on ArcGIS.com and add data from here:
And it created a nice map. Now when I try, I get a "taking a long time to respond" warning followed by an error saying it cannot be added. I don't think I did anything to our ArcServer. I asked a few other AGO users to try and they saw the same results. I rebooted our server. I can add the same service to ArcGIS desktop with no trouble. Finally I tried a completely different server:
It does the same thing. Am I doing something fundamentally wrong or did I break the Internet?