You are trying to use code from the 2003 version which no longer applies
Try this (ON A COPY!)
Sub apply_CL() Dim L As Long ActivePresentation.Slides(1).CustomLayout = ActivePresentation.SlideMaster.CustomLayouts(1) For L = 2 To ActivePresentation.Slides.Count ActivePresentation.Slides(L).CustomLayout = ActivePresentation.SlideMaster.CustomLayouts(2) Next L End Sub