How to solve exception "File does not exist"?

Question

I have a basic ASP.NET MVC2 site which logs a single "File does not exist" error every time a view (not partial views) is loaded. I am pretty sure this is because I am referencing a file, from the master page, that does not exist, but I cannot figure out which one it is.

The stack trace is not useful (see below). Does anyone have any tips on how to best debug this?

File does not exist. :    at System.Web.StaticFileHandler.GetFileInfo(String virtualPathWithPathInfo, String physicalPath, HttpResponse response)
   at System.Web.StaticFileHandler.ProcessRequestInternal(HttpContext context)
   at System.Web.DefaultHttpHandler.BeginProcessRequest(HttpContext context, AsyncCallback callback, Object state)
at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

Answer 1

As you say, its probably a missing file or image referenced by your master page. To capture the error, add the following error handler to your Global.asax

protected void Application_Error(object sender, EventArgs e)
{
    Exception ex = Server.GetLastError();

    if (ex.Message == "File does not exist.")
    {
        throw new Exception(string.Format("{0} {1}", ex.Message, HttpContext.Current.Request.Url.ToString()), ex);
    }
}

This should then tell you what resource the page is requesting