Due to new render window names.
The issue was already mentioned in {T29203} but will now be tackled separately here after the next release.
The MovieMaker plugin (and associated classes like `QmitkSliceAnimationWidget`, `QmitkSliceAnimationItem`, `QmitkOrbitAnimationItem`) need to be refactored and tested. Since this is a broader topic, this issue was decoupled from the mentioned task.