title: Microsoft Edge ignoring content disposition response header's FileName property?
body: <p>I'm sending a file to the browser to be saved locally. This works fine in all browsers except Microsoft Edge, where it replaces the filename with a guid. The file has to be downloaded with a specific filename, is there an explanation or workaround for this problem? My answer "don't use Edge" will be rejected.</p>
  
  <pre><code>        var response = new HttpResponseMessage(HttpStatusCode.OK)
          {
              Content = new ByteArrayContent(CreateFile(fileContents))
          };
          response.Content.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");
          response.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment")
          {
              FileName = string.Concat(fileName, ".xlsx")
          };
  </code></pre>