title: Visual Studio editor not showing any text
body: <p>I have been using VS for many years.  Today I have encountered a very strange problem with visual studio 2013. Suddenly for some reason I am unable to see any text in the editor window.  I've tried reloading the files, redocking each window, restarting VS, restarting my machine and resetting all my settings in Tools -> Import and Export Settings.  At present I'm completely stuck as I can't do anything.  The tab for each opened file appears at the top as expected but just a blue pane. I'm hoping this is something daft! </p>
  
  <p><img src="https://i.stack.imgur.com/JYaPM.jpg" alt="enter image description here"></p>