         self.networkModel.fetchLotStanding().next { [weak self] lotStandings in
             saleViewModel.updateLotStandings(lotStandings)
 
-            if let existingLotStandingsView = self?.headerStack.viewWithTag(ViewTags.lotStandings.rawValue) {
-                self?.headerStack.removeSubview(existingLotStandingsView)
+            if let existingLotStandingsView = self?.headerStack?.viewWithTag(ViewTags.lotStandings.rawValue) {
+                self?.headerStack?.removeSubview(existingLotStandingsView)
             }
 
             self?.addLotStandings()

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)

        guard appeared == false else {
            // Re-appearing, so re-fetch lot standings and update.
            fetchLotStandingsAndUpdate()
            return
        }
        appeared = true

        self.ar_presentIndeterminateLoadingIndicator(animated: animated)

        let liveCV = ARSwitchBoard.sharedInstance().loadLiveAuction(saleID)

        ARTopMenuViewController.shared().push(liveCV!, animated: true) {
            _ = self.navigationController?.popViewController(animated: false)
        }
    }

