Issue with List Array

Try this:-

Sub MG24Mar35
Dim MyArray As Variant

MyArray = ThisWorkbook.Sheets("Sheet1").Range("N2:N663").value

With ThisWorkbook.Sheets("sheet1").Range("N1").Validation
.Delete
.Add Type:=xlValidateList, Operator:=xlBetween, Formula1:=Join(Application.Transpose(MyArray), ",")
.IgnoreBlank = True
.InCellDropdown = True
.InputTitle = ""
.ErrorTitle = ""
.InputMessage = ""
.ErrorMessage = ""
.ShowInput = True
.ShowError = True
End With
End Sub

Regards Mick