vb.net: variable is passed by reference before it has been assigned a value

Имеется проблема. Получаю ошибку (0x80004005) The method GetItem failed.

Сам код:

        Dim Documents2 = CATIA.Documents
        dim CurrentFileName2 
        dim Prod = 11
        dim Part = 8

        For Each Item In Documents2
            If Item.Name.Substring(Item.Name.Length - 10) = "CATProduct" Then
                CurrentFileName2 = Item.Name.Substring(Item.Name.Length - Prod)
            ElseIf Item.Name.Substring(Item.Name.Length - 7) = "CATPart" Then
                CurrentFileName2 = Item.Name.Substring(Item.Name.Length - Part)'"yy"
            End If

            dim CurrentPart2 = Item.GetItem(CurrentFileName2) <-- тут в скобках получаю 
            это ->>>>variable is passed by reference before it has been assigned a value

            CurrentPart2.PartNumber = CurrentFileName2

        Next

Что тут не так?