Problème mathématique

Sub Colorie_Espace_Etendue()
'Stop
'Mj
For i = 5 To Range("D65536").End(xlUp).Row Step 6
'Stop
Cells(i, 4).Select
    deb = Int(ActiveCell.Offset(-1, -1).Value)
    fin = Int(ActiveCell.Offset(0, -1).Value)
        Set refdeb = Cells(ActiveCell.Row, 4 + deb + 1)
        Set reffin = Cells(ActiveCell.Row, 4 + fin)
    Coulplage = Cells(ActiveCell.Row, 45).Interior.Color
With Range(refdeb, reffin)
    .Interior.Color = Coulplage
    .Borders(xlEdgeRight).LineStyle = xlContinuous
    .Borders(xlEdgeRight).Weight = xlMedium
    .Borders(xlEdgeLeft).LineStyle = xlContinuous
    .Borders(xlEdgeLeft).Weight = xlMedium
End With
Next
End Sub
Sub Copie_Feuille_Et_Supprime_Lignes_Inutiles()
'stop
'Mj
   ActiveSheet.Copy After:=Sheets(1)
    Cells.Select
    Selection.Copy
    Selection.PasteSpecial Paste:=xlPasteValues, Operation:=xlNone, SkipBlanks _
        :=False, Transpose:=False
    Application.CutCopyMode = False
    Columns("A:C").Select
    Selection.Delete Shift:=xlToLeft
    Columns("AM:AQ").Select
    Selection.Delete Shift:=xlToLeft
    Range("A1").Select
    For i = [A65536].End(xlUp).Row To 1 Step -1
        If Cells(i, 255).End(xlToLeft).Column = 1 Then Rows(i).Delete Shift:=xlUp
    Next
    ActiveWindow.DisplayGridlines = False
End Sub