Hi i am using Autocad 2014 API facing some issues in autocad 2014 API.while assign Freeze property is false on first layer  through coding i am getting error message  invalid layer.Please help on that.Please see the below VB.Net code  For Each objLayer As Autodesk.AutoCAD.Interop.Common.AcadLayer In Acad.ActiveDocument.Layers                objLayer.LayerOn = True                objLayer.Freeze = False                    Next objLayer