AddItem and Clear Giving Errors when Run

Hi All

I am trying to use the AddItem to create a List from a named Range. But when I run the form I am getting Compile Error: Method or Data Member not Found.
I have this code running successfully in another spreadsheet fine.
I am using excel 2010 and the spread was originally setup in Excel 2003

Private Sub UserForm_Initialize()

    Dim ListItems As Variant, i As Integer
    
    Class.Value = ""
    Class_Name.Value = ""
    Entry_Fee.Value = ""
    
   With Me.Day
        .Clear
       ListItems = Range("HacksPoniesDays").Value
       ListItems = Application.WorksheetFunction.Transpose(ListItems)
       For i = 1 To UBound(ListItems)
          .AddItem ListItems(i)
           Next i
       .ListIndex = -1
   End With
    
        With Me.Prize_List
        .Clear
        ListItems = Range("Hacksprize").Value
        ListItems = Application.WorksheetFunction.Transpose(ListItems)
        For i = 1 To Unbound(ListItems)
            
            .AddItem ListItems(i)
             Next i
        .ListIndex = -1
    End With
        
        
    Day.SetFocus
End Sub

Any help thanks

Tony