title: IFormFileCollection is null when adding file to Flurl multi-part POST request
body: <p>I am trying to upload a file using Flurl using <code>AddFile</code>.</p>
  
  <p>The resulting <code>IFormFileCollection</code> is null, although I am able to see the item when looking at <code>Request.Form.Files[0]</code> with the right content length.</p>
  
  <p>Creating the request:</p>
  
  <pre><code>public Task&lt;HttpResponseMessage&gt; UploadImage(string fileName, MemoryStream stream)
  {
      stream.Position = 0;
  
      _baseUrl
          .AppendPathSegments("uploadImage")
          .PostMultipartAsync(mp =&gt; mp
              .AddFile("files", stream, fileName))
  }
  </code></pre>
  
  <p>Handling the request:</p>
  
  <pre><code>[HttpPost]
  [Route("uploadImage")]
  public async Task&lt;HttpResponseMessage&gt; UploadImages([FromForm] IFormFileCollection files)
  {
      //files is null, but Request.Form.Files[0] in the immediate window shows the file.
  }
  </code></pre>
  
  <p>A common problem seems to be a mismatch in the name of the parameter and the name in the Content-Disposition header, but I updated them to both be <code>files</code> and I am still having the same issue.</p>