title: ASP.NET MVC / IIS 7.5: 500 Internal Server Error for static content only
body: <p>An ASP.NET MVC project running under IIS 7.5 (but problem may exist on earlier versions and non-MVC sites) which was previously working has started returning 500 Internal Server Error but only for content handled by the static handler - images, pages etc. handled by MVC itself through a controller work fine. </p>
  
  <p>I know what caused it - I am documenting this in case somebody else has the same problem.</p>