That's strange. I don't get any errors like that. Here's what I did to try it out.

Start a new standard EXE project. Add one checkbox and set its index property to 0 (zero). Add a command button to the form and put the following codde in its click event:
Code:
Private Sub Command1_Click()
    Dim X As Variant
    Dim iCount As Integer

    Set X = Check1
    iCount = X.Count
    Load X(iCount)
    With X(iCount)
        .Move .Left, X(iCount - 1).Top + .Height
        .Visible = True
    End With
End Sub
Now, every time you click on the CommandButton it load an other CheckBox.

Best regards