With first macOS Catalina version, I have implemented NSSharingServicePickerToolbarItem but after macOS 10.15.1 update this don't work anymore. I have implemented MasterViewController as activityItemConfiguration conforming UIActivityItemsConfigurationReading protocol. Error trace 2020-06-19 10:38:29.655949+0200 WhatsHappen[11969:112649] [General] -[WhatsHappen.MasterViewController _uinsApplicationActivityProxies]: unrecognized selector sent to instance 0x100e1ab00 2020-06-19 10:38:29.656468+0200 WhatsHappen[11969:112649] [General] ( 0   CoreFoundation                      0x00007fff3744abe7 __exceptionPreprocess + 250 1   libobjc.A.dylib                     0x00007fff702225bf objc_exception_throw + 48 2   CoreFoundation                      0x00007fff374c9c77 -[NSObject(NSObject) __retain_OA] + 0 3   UIKitCore                           0x00007fff788e0c80 -[UIResponder doesNotRecognizeSelector:] + 310 4   CoreFoundation                      0x00007fff373af44b _forwarding_ + 1427 5   CoreFoundation                      0x00007fff373aee28 _CF_forwarding_prep_0 + 120 6   UIKitMacHelper                      0x00007fff6866bb5e UINSConfigureSharingToolbarItemWithActivityItemsConfiguration + 286 7   UIKitCore                           0x00007fff7884b9ef -[NSSharingServicePickerToolbarItem(UIActivityItemsConfiguration) setActivityItemsConfiguration:] + 56 Implementation Share item configuration let shareItem = NSSharingServicePickerToolbarItem(itemIdentifier: .share)             guard let splitViewController = rootViewController else { return nil }             guard let navigationController = splitViewController.viewControllers.first as? UINavigationController else { return nil }             guard let masterViewController = navigationController.topViewController as? MasterViewController else { return nil }             shareItem.activityItemsConfiguration = masterViewController             return shareItem 2. Protocol conforming extension MasterViewController: UIActivityItemsConfigurationReading {     var itemProvidersForActivityItemsConfiguration: [NSItemProvider] {         if let selected = tableView.indexPathForSelectedRow, let articles = fetchedResultsController.fetchedObjects {             return [articles[selected.row].itemProvider]         }         return []     } } 3. Item provider var itemProvider: NSItemProvider { NSItemProvider(object: link as NSURL? ?? NSURL()) }