title: F12 -- Goto Definition does not work with Visual Studio 2015
body: <p>Has anyone run into this before? In my freshly installed copy of Visual Studio 2015 Professional I simply cannot get 'F12 - Goto Definition' to work. Nothing happens when I try it. What is more, if I try 'ALT-F12 -- Peek at definition', I just get a blank window saying "A definition for the symbol '(null)' could not be located'. Intellisense is working fine. I do not have a lot of third party tools installed (except some git related ones). I am at my wit's end here.</p>
  
  <p>Can anyone help? I have already re-installed this twice.</p>