m_width = (rt.rect.width + _cellGap) * _canvasRect.localScale.x;
UnassignedReferenceException: The variable _canvasRect of CarouselController has not been assigned.
You probably need to assign the _canvasRect variable of the CarouselController script in the inspector.
UnityEngine.Transform.get_localScale () (at <7559bf9767e74ff5906f18401f66cd57>:0)
CarouselController.SetupCells (System.Boolean instantUpdate) (at Assets/CarouselMenu/Scripts/CarouselController.cs:251)