Subscript out of range problem

[Kerry H]

Can you see why the following code generates a "subscript out of range" error at the last line?
The Sheets(Sh) convention works elsewhere. The Rng1A.copy seems to have taken place ok.

Dim Rng1A, Rng2A, Rng1I, Rng2I As Range   'range blocks to copy
Dim N as Long, D As Date, Sh As String
N = ActiveWorkbook.Sheets("NAVIGATION").Range("G12")   ' value is correct
        D = ActiveWorkbook.Sheets("NAVIGATION").Range("H13")    ' value is correct
        Sh = "Sheet" & N                                                                ' value is correct
With ActiveWorkbook.Sheets("INV ACC")
            Set Rng1A = Range("D15:I214") 
            Set Rng2A = Range("M15:W214") 
        End With
With ActiveWorkbook.Sheets("INV INPUT")
            Set Rng1I = Range("H15:L214")  
            Set Rng2I = Range("S15:Y214")  
        End With
Rng1A.Copy
            Workbooks("Centris Periods.xlsm").Sheets(Sh).Range("D15:I214").PasteSpecial xlPasteValuesAndNumberFormats

Thank very much.