Erreur 1004 suit a l'ajout d'une ligne numéroté automatiquement

Private Sub CommandButton21_Click()
fin = Feuil2.Range("B" & Rows.Count).End(xlUp).Row + 1
Feuil2.Rows(fin).Insert
fin = Feuil2.Range("B" & Rows.Count).End(xlUp).Row + 1
Range("B" & fin) = Range("B" & fin - 1) + 1
Range("A" & fin & ":l" & fin).Borders(xlDiagonalDown).LineStyle = xlNone
Range("A" & fin & ":l" & fin).Borders(xlDiagonalUp).LineStyle = xlNone
Range("A" & fin & ":l" & fin).Select
    With Selection.Borders
        .LineStyle = xlContinuous
        .Weight = xlThin
        .ColorIndex = xlAutomatic
    End With
End Sub

Option Explicit
Private Sub CommandButton21_Click()
    If [b4] = "" Then [b4] = 1
    Range("b" & Rows.Count).End(xlUp).Resize(, 11).Copy Destination:=Range("b" & Rows.Count).End(xlUp)(2)
    Range("b" & Rows.Count).End(xlUp).Offset(, 1).Resize(, 10) = ""
    With Range("b" & Rows.Count).End(xlUp): .Value = .Offset(-1, 0).Value + 1: End With
End Sub