Pesky "Object Required" error

I am trying to determine what I call the "DefaultCell" of a given range, which is the upper left most cell of the range the user selects. When I run the selection through the code below for the second selection, I get the "Object required" error, and I can't target why. For the first range selection, its fine though.

Private Function GetDefaultCell() As String

    'returns address of previous range's first cell (upper left)
    
    Dim firstCell As Range
    
    If (UserRanges.Count <> 0) Then
        firstCell = UserRanges.Item(UserRanges.Count).Cells(1, 1)
        GetDefaultCell = GetFullAddress(firstCell)
    Else
        GetDefaultCell = ""
    End If
    

End Function