title: Sharing Video PHAsset via UIActivityController
body: <p>I am trying to share video <strong>PHAsset</strong> via <strong>UIActivityController</strong> using requestAVAsset. This works with Messaging, but not with AirDrop, indicating as 'Failed'.</p>
  
  <pre><code>PHCachingImageManager.default().requestAVAsset(forVideo: asset, options: nil, resultHandler:
      { (givenAsset, audioMix, info) in
  
          let videoAsset = givenAsset as! AVURLAsset
          let videoURL = videoAsset.url
  
          DispatchQueue.main.async {
              let activityViewController = UIActivityViewController(
                  activityItems: [videoURL],
                  applicationActivities: nil)
              activityViewController.excludedActivityTypes = [UIActivityType.saveToCameraRoll]
  
              if let popoverPresentationController = activityViewController.popoverPresentationController {
                  popoverPresentationController.barButtonItem = (sender)
              }
  
              self.present(activityViewController, animated: true, completion: nil)
          }
  })
  </code></pre>
  
  <p>This seems to properly put up <strong>UIActivityController</strong> and only work with certain activities:  </p>
  
  <ul>
  <li><strong>Messaging</strong> - ✔️Works, properly exports video.</li>
  <li><strong>AirDrop</strong> - ✖️Shows "Failed"</li>
  <li><strong>Dropbox</strong> - ✖️Puts up the proper Dropbox View, yet says "Unknown error occurred"</li>
  </ul>
  
  <hr>
  
  <p><a href="https://i.stack.imgur.com/nUSSI.png" rel="noreferrer"><img src="https://i.stack.imgur.com/nUSSI.png" alt="enter image description here"></a></p>