What is the range of valid zoom factors in NDrawingView.Zoom method?
I am passing a float value in the 0 to 1 range. However occasionally getting the error:
 System.ArgumentException: The specified zoom factor is not valid
 Parameter name: zoom
 at Nevron.Diagram.WinForm.NDrawingView.Zoom(Single zoom, NPointF viewportCenter)

Was having the same problem myself. You need to make sure that the MinZoomFactor and MaxZoomFactor are set or else Zoom will not accept your zoom factor. They are NDrawingDocument.Settings.MinZoomFactor and NDrawingDocument.Settings.MaxZoomFactor.