When opening an MVC4 C# web project in Visual Studio 2013, the IDE reports the error \"The type or namespace name \'_\' could not be found (are you missing a using
There's a known issue with Web Application projects when bound to a TFS server that sounds like this issue. This occurs when the following TFS setting option is checked:
Options -> Source Control -> Environment -> Get everything when a solution or project is opened.
Disabling this option resolves the problem.
thanks, Miguel Lacouture [MSFT]