VBA code error for userform dependent combobox

Hello,

I'm trying to create a dependent combox on a userform, as followed in the tutorial on excel-easy.com, the contents of the second combobox are dependent on the selection in the first:

Private Sub cbo1_change()
    Me.Cbo2.Clear
    Dim index As Integer
    index = cbo1.ListIndex
    Select Case index
    Case Is = 0
                With Me.Cbo2
                .AddItem "Custom"
                End With
        
        Case Is = 1
            With Me.Cbo2.Value
                .AddItem "Free"
                End With

It works with the first selection,when I select "custom" in the first combobox, but then when I select "Free" in the first combobox, I get the error message 'run time 424 - object required'. I thought the object was already defined - in the listfill range in combobox1:

With ws
.cbo1.ListFillRange = "A2:A7"
End With

Any ideas?