XL 2016 Problème d'ouverture d'userform

Dim f As Worksheet


Private Sub UserForm_Initialize()
'Dim f As Feuil12
  Me.Source.MultiSelect = fmMultiSelectMulti
  Set f = Sheets("Mouvement")
  Me.ListBox1.List = Array("Inscription sur listing", "Départ PC pour effectuer mission", "Entrée dans la cavité", "Sortie de la cavité", "Retour PC pour signaler fin mission", "Quitte le site")
  Me.ListBox1.ListIndex = 0
  Me.Destination.Caption = Me.ListBox1.List(0)
  Me.Destination.TextAlign = fmTextAlignRight
  p = Me.ListBox1.ListIndex
  n = f.[A65000].Offset(, p * 3).End(xlUp).Row
  If n > 1 Then Me.Source.List = f.Range("A2:B" & n).Offset(, p * 3).Value Else Me.Source.Clear
  n = f.[D65000].Offset(, p * 3).End(xlUp).Row
  If n > 1 Then Me.Dest.List = f.Range("D2:E" & n).Offset(, p * 3).Value Else Me.Dest.Clear
  '---histo
  n = f.[V65000].End(xlUp).Row
  If n > 1 Then Me.Historique.List = f.Range("V2:Y" & n).Value Else Me.Historique.Clear
  Me.Source.Visible = False
  Me.b_prend.Visible = False

End Sub

Private Sub CommandButton1_Click()
Concatene
UserForm2.TextBox4.Value = f.[N1].Value
Me.Main.Clear
Unload Me
UserForm2.Show
End Sub

Sub Concatene()
Dim Cel As Range, Co As Range
Dim Lg, i As Long
Application.ScreenUpdating = False
With Sheets("Mouvement")
k = [S1]
    If k > 0 Then
      For i = 2 To k + 1
      .Range("O" & i).Select
      ActiveCell.FormulaR1C1 = "=CONCATENATE(RC[3],"" de "",RC[2],"" à "",RC[4])"
    Next i
    End If
Lg = [O65536].End(xlUp).Row
  
    With Sheets("Mouvement").Range("N1")
      .ClearContents
      For Each Cel In Range("O2:O" & Lg)
        If Cel <> "" Then
        .Value = .Value & Cel.Value & Chr(10)
        Else: Exit For
        End If
      Next Cel
    End With
    End With
End Sub