Baseitem sollte nicht NULL sein

baseItemsollte nicht NULL sein.System.Exception: baseItemsollte nicht NULL sein.
  at HighTreason.Libraries.Common.Guard.IsNotNull(Object obj, String param)
  at HighTreason.WindowsStore.GameControl.Helpers.ItemChainHelper.GetLastAttached[T](ImageItem2D baseItem)
  at HighTreason.WindowsStore.GameControl.Helpers.SinkPreventer.PreventSink(ImageItem2D parent, Dictionary`2 layerImageMap)
  at HighTreason.Libraries.WorldModel.Stair2D.Move(SizeF2D size, Boolean updateMovingDirection, Boolean moveChilds, Boolean moveWayPoints)
  at HighTreason.Libraries.WorldModel.ImageItem2D.Move(SizeF2D size, Boolean updateMovingDirection, Boolean moveChilds, Boolean moveWayPoints)
  at HighTreason.Libraries.WorldModel.Stair2D.Move(SizeF2D size, Boolean updateMovingDirection, Boolean moveChilds, Boolean moveWayPoints)
  at HighTreason.Libraries.WorldModel.ImageItem2D.Move(SizeF2D size, Boolean updateMovingDirection, Boolean moveChilds, Boolean moveWayPoints)
  at HighTreason.Libraries.WorldModel.Stair2D.Move(SizeF2D size, Boolean updateMovingDirection, Boolean moveChilds, Boolean moveWayPoints)
  at HighTreason.Libraries.WorldModel.ImageItem2D.Move(SizeF2D size, Boolean updateMovingDirection, Boolean moveChilds, Boolean moveWayPoints)
  at HighTreason.Libraries.WorldModel.ImageItem2D.Move(SizeF2D size, Boolean updateMovingDirection, Boolean moveChilds, Boolean moveWayPoints)
  at HighTreason.Libraries.WorldModel.ImageItem2D.Move(SizeF2D size, Boolean updateMovingDirection, Boolean moveChilds, Boolean moveWayPoints)
  at HighTreason.Libraries.WorldModel.WallBase.DestroyTimerElapsed()
  at HighTreason.Libraries.Common.XnaTimer.Update(TimeSpan time)
  at HighTreason.Libraries.WorldModel.WallBase.Update(TimeSpan simulationTime, TimeSpan gameTime)
  at HighTreason.WindowsStore.GameControl.GameController.Update(TimeSpan simulationTime, TimeSpan gameTime)
  at HighTreason.WindowsStore.Game.Game.Update(GameTime gameTime)

Thank you lord1!
I'll fix this bug over weekend.
If everything goes as usual the new version will be ready on thuesday 6th October.

The bug fix is on the way.
I hope the guys at Microsoft do their job quickly :-)

An error has occured.

baseItem should not be NULL.System.Exception: baseItem should not be NULL.
  at HighTreason.Libraries.Common.Guard.IsNotNull(Object obj, String param)
  at HighTreason.WindowsStore.GameControl.Helpers.ItemChainHelper.GetLastAttached[T](ImageItem2D baseItem)
  at HighTreason.WindowsStore.GameControl.Helpers.RemoveHelper.OnRememberItemToRemove(WorldItem2D item)
  at HighTreason.WindowsStore.GameControl.GameController.RememberItemToRemove(WorldItem2D item)
  at HighTreason.Libraries.WorldModel.WallBase.DestroyTimerElapsed()
  at HighTreason.Libraries.Common.XnaTimer.Update(TimeSpan time)
  at HighTreason.Libraries.WorldModel.WallBase.Update(TimeSpan simulationTime, TimeSpan gameTime)
  at HighTreason.WindowsStore.GameControl.GameController.Update(TimeSpan simulationTime, TimeSpan gameTime)
  at HighTreason.WindowsStore.Game.Game.Update(GameTime gameTime)

Thank you abhishan for your Bugreport! I just fixed it, but it will take 2-3 weeks to publish the next release, because I have to finish some work. It will be available second half of december 2015. Thanks for your help!