File display inline throws 'Could not find part of path'

I am creating an ASP.NET MVC 4 application that should allow the user to display a PDF in a browser (not offered for download) in Chrome. I've used the following answers to help me build it so far:

• Stackoverflow question - Save dialog pops up
• Stackoverflow question - as above

Here's the action in my controller:

public ActionResult DownloadPdf()
{
    var mimeType = "application/pdf";
    var filepath = Server.MapPath(Url.Content("~/downloads/"));
    var filename = "Sample.pdf";
    Response.Headers.Remove("Content-Disposition");
    Response.AppendHeader("Content-Disposition", "inline; filename=" + filename);
    return File(filepath, mimeType);
}

      

        
        
        
      

    

And here's where JavaScript is called to open a new window with an embedded file:

function downloadPdf() {
    var path = '@Url.Action("DownloadPdf")';
    window.open(path, '_blank');
}

      

        
        
        
      

    

Using the above code, a new window (tab) opens in Chrome with the exception:

Could not find part of path 'C: \ _ Projects \ myapp \ PDFHandler \ downloads \'.

But the Sample.pdf file is in this folder. I read that in order to open an embedded file, we don't need to provide a filename to the method File()

. If I change the above file path and name, the error goes away, but then it prompts me again for the Save dialog in Chrome.