NullReferenceException: Object reference not set to an instance of an object.
StackTrace:
   at Quicker.Utilities.AppHelper.<FindRootWindows>d__109`1.MoveNext()
   at System.Linq.Enumerable.Any[TSource](IEnumerable`1 source)
   at Quicker.Utilities.AppHelper.EXZoXpbiJ5X()
   at Quicker.App.<OnSessionEnding>d__29.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   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)