Ok, while setting up an instance of Team Foundation Server 2013 RC. I ran into a weird error while trying to create my first Team Project for my brand new Team Project Collection. This one had me stumped for a few minutes. So to give you some background, here are the steps that I was using when I received this error.
I knew for a fact that my project name was not already in use. So I immediately opened up IE and when to Bing to find out what was going on. I found a blog post stating that this error was misleading. No surprise there! So I checked that I could connect to Central Admin on my SharePoint instance. Sure enough I could. Okay I thought, can I get to the DefaultCollection site in SharePoint? Yes I could.
Luckily I have debugged SharePoint quite a bit in my SharePoint developer days. So I opened up the SharePoint ULS log and scrolled to the bottom. That is where I found the real problem. I found a warning stating that Alternate access mappings have not been configured. Now, if you are on your local network this probably would not affect you. But in my case, my TFS Instance is hosted in Azure as a VM. More coming on that topic, stay tuned!
So the solution was to go into Central Admin and add an Alternate access mapping for the default site collection. I added the Azure VM URL to the Internet Public URLs. Once I added that, all was good with TFS and Visual Studio.
Hopefully this will help someone out there but at a minimum, it will help me if I ever run into this issue again.