The new MxN MultiWidget provides a utility toolbar at the top of each render window which allows to scroll through the visible slices.
Depending on the geometry, the scrolling needs to be inverted; this happens inside QmitkRenderWindowUtilityWidget::SetGeometry if a new geometry is received via the corresponding slice navigation controller.

In this function a timestep is extracted from the given time geometry. However, since the timestep is global, it might be that a timestep should be extracted that is not available for this specific time geometry (because the time step was selected with a different render window / time geomtry).
This will lead to a crash, so we need to take care of that. This should be done in combination with T29273: Decouple TimeNavigation from SliceNavigationController (when D705 is tested and landed).