From when Visual Studio started treating 200 OK as Http Errors?

From when Visual Studio started treating 200 OK as Http Errors?

Recently I encountered a strange error dialog in Visual Studio TFS. All of a sudden it threw a messagebox that that it encountered a 200 OK from the server. :) See attachment. The other day I had fiddler open in my system and I could see web service requests carrying checkin/checkouts of the files from Visual Studio.

It is really excellent that Microsoft is extending patronage and embracing an Open XML format for Visual Studio too.