title: Dropzone send empty
body: <p>I have a dropzone setup with the following script:</p>
  
  <pre><code>    &lt;script&gt;
      Dropzone.options.myDropzone = {
          url: 'assets/PHP/createNieuws.php',
          autoProcessQueue: false,
          uploadMultiple: true,
          parallelUploads: 1,
          maxFiles: 1,
          maxFilesize: 1,
          acceptedFiles: 'image/*',
          addRemoveLinks: true,
          createImageThumbnails: true,
          init: function () {
              dzClosure = this; // Makes sure that 'this' is understood inside the functions below.
  
              this.on("success", function (file, responseText) {
                  console.log(responseText);
              });
  
              // for Dropzone to process the queue (instead of default form behavior):
              document.getElementById("submit").addEventListener("click", function (e) {
                  // Make sure that the form isn't actually being sent.
                  e.preventDefault();
                  e.stopPropagation();
                  if (dzClosure.getQueuedFiles().length &gt; 0) {
                      dzClosure.processQueue();
                  } else {
                      dzClosure.uploadFiles([{ name: 'nofiles' }]); //send empty
                  }
              });
  
              //send all the form data along with the files:
              this.on("sendingmultiple", function (data, xhr, formData) {
                  formData.append("titel", jQuery("#titel").val());
                  formData.append("artikel", jQuery("#artikel").val());
              });
          }
      }
  &lt;/script&gt;
  </code></pre>
  
  <p>And i also have a file named default.png on my server. I would like dropzone to refer to default.png if no image is detected. As you can see i've tryed this solution already to no succes: <a href="https://stackoverflow.com/a/41044001/6396380">https://stackoverflow.com/a/41044001/6396380</a></p>
  
  <p>This returns the following error in my chrome console:</p>
  
  <p>dropzone.js:1497 Uncaught TypeError: Cannot read property 'filename' of undefined</p>
  
  <p>My dropzone version is 5.1.0 .</p>
  
  <p>Any idea's on how to fix this?</p>