Object reference not set to an instance of an object.

[realworld666]

System.NullReferenceException: Object reference not set to an instance of an object.
   at Cyclestreets.Managers.RouteManager.HasCachedRoute(String defaultPlan)
   at Cyclestreets.CustomClasses.CycleStreetsMap.Map_Loaded(Object sender, RoutedEventArgs e)
   at MS.Internal.CoreInvokeHandler.InvokeEventHandler(Int32 typeIndex, Delegate handlerDelegate, Object sender, Object args)
   at MS.Internal.JoltHelper.FireEvent(IntPtr unmanagedObj, IntPtr unmanagedObjArgs, Int32 argsTypeIndex, Int32 actualArgsTypeIndex, String eventName)