 
     required init?(coder aDecoder: NSCoder) {
         fatalError("init(coder:) has not been implemented")
+    }
+
+    override func viewDidDisappear(_ animated: Bool) {
+        super.viewDidDisappear(animated)
+        webView?.navigationDelegate = nil
+        self.webView = nil
     }
 
     override func viewDidLoad() {


    fileprivate var screenShot: UIImageView?
    fileprivate var previewAccessibilityLabel: String!

    // Preview action items.
    override var previewActionItems: [UIPreviewActionItem] {

        }

        clonedWebView.navigationDelegate = self
        self.webView = clonedWebView
        clonedWebView.load(URLRequest(url: url))
    }

