after update i am getting this error how can i fix
Message = Object reference not set to an instance of an object.
Error = System.NullReferenceException
Full text = System.NullReferenceException: Object reference not set to an instance of an object.
at System.Windows.Automation.Peers.AutomationPeer.EnsureChildren()
at System.Windows.Automation.Peers.AutomationPeer.UpdateChildrenInternal(Int32 invalidateLimit)
at System.Windows.Automation.Peers.ItemsControlAutomationPeer.UpdateChildren()
at System.Windows.Automation.Peers.AutomationPeer.UpdateSubtree()
at System.Windows.Automation.Peers.AutomationPeer.UpdateSubtree()
at System.Windows.Automation.Peers.AutomationPeer.UpdateSubtree()
at System.Windows.ContextLayoutManager.fireAutomationEvents()
at System.Windows.ContextLayoutManager.UpdateLayout()
at System.Windows.Controls.VirtualizingStackPanel.<>c__DisplayClass94_0.<InitializeViewport>b__0()
at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)
