Incorrect IIS IP Bindings and TFS Server Url
By default the TFS server uses http://localhost:8080/tfs as it’s Server URL, this is the URL used for internal communication, whereas the Notification Url is the one TFS tells client to communicate to it via. Both these Urls can be changed via the Team Foundation Server Console, but I find you do not usually need to change the Server Url, only the notification one. I hit a problem recently on a site where if you tried to edit the Team Project Collection Group Membership (via the web or TFS admin console) you got a dialog popping up saying ‘HTTP 400 error’. Now this you have to say looks like a URL/binding issue, the tools cannot find an end point. ...