Excel bricht beim ausführen der Schleife zusammen

Private Sub Schaltflächen()
Dim I, X, StartMon, EndeMon, Abst As Integer
Dim Bttn As String
Dim modul As Object
Dim Mon(1 To 12) As String
Mon(1) = "Januar"
Mon(2) = "Februar"
Mon(3) = "März"
Mon(4) = "April"
Mon(5) = "Mai"
Mon(6) = "Juni"
Mon(7) = "Juli"
Mon(8) = "August"
Mon(9) = "September"
Mon(10) = "Oktober"
Mon(11) = "November"
Mon(12) = "Dezember"
StartMon = 2
EndeMon = 12
For I = StartMon To EndeMon
Worksheets(Mon(I)).OLEObjects.Add(ClassType:="Forms.CommandButton.1", Link:=False _
, DisplayAsIcon:=False, Left:=375, Top:=2, Width:=120, Height _
:=22).Select
Worksheets(Mon(I)).OLEObjects("CommandButton1").Object.Caption = "Alle Spalten einblenden"
Worksheets(Mon(I)).OLEObjects("CommandButton1").Placement = xlFreeFloating
Worksheets(Mon(I)).OLEObjects.Add(ClassType:="Forms.CommandButton.1", Link:=False _
, DisplayAsIcon:=False, Left:=375, Top:=28, Width:=120, Height _
:=22).Select
Worksheets(Mon(I)).OLEObjects("CommandButton2").Object.Caption = "Alle Spalten ausblenden"
Worksheets(Mon(I)).OLEObjects("CommandButton2").Placement = xlFreeFloating
Abst = 144
For X = 0 To 4
Bttn = "CommandButton" & X + 3
Worksheets(Mon(I)).OLEObjects.Add(ClassType:="Forms.CommandButton.1", Link:=False _
, DisplayAsIcon:=False, Left:=375 + X * Abst, Top:=54, Width:=22, Height:=22). _
Select
Worksheets(Mon(I)).OLEObjects(Bttn).Object.Caption = "X"
Worksheets(Mon(I)).OLEObjects(Bttn).Object.Font.Bold = True
Worksheets(Mon(I)).OLEObjects(Bttn).Placement = xlMoveAndSize
Next X
Set modul = ThisWorkbook.VBProject.VBComponents.Item(Worksheets(Mon(I)).CodeName). _
CodeModule
modul.insertlines 3, "

Private Sub CommandButton1_Click()"
modul.insertlines 4, "spein"
modul.insertlines 5, "End Sub
"

modul.insertlines 6, "

Private Sub CommandButton2_Click()"
modul.insertlines 7, "spaus"
modul.insertlines 8, "End Sub
"

modul.insertlines 9, "

Private Sub CommandButton3_Click()"
modul.insertlines 10, "spkaus"
modul.insertlines 11, "End Sub
"

modul.insertlines 12, "

Private Sub CommandButton4_Click()"
modul.insertlines 13, "spmaus"
modul.insertlines 14, "End Sub
"

modul.insertlines 15, "

Private Sub CommandButton5_Click()"
modul.insertlines 16, "spoaus"
modul.insertlines 17, "End Sub
"

modul.insertlines 18, "

Private Sub CommandButton6_Click()"
modul.insertlines 19, "spqaus"
modul.insertlines 20, "End Sub
"

modul.insertlines 21, "

Private Sub CommandButton7_Click()"
modul.insertlines 22, "spsaus"
modul.insertlines 23, "End Sub
"

Next I

End Sub