'The festival lacks structure' is a much more natural translation in english and should definitely be accepted.
[17/05/15] Look at these examples:
- There is no structure in the festival = Não tem estrutura no festival.
There is/are = "Ter, Haver, Existir" in the sense of exist something.
- The festival has no structure/ The festival doesn't have structure = O festival não tem estrutura.
Have/Has = "Ter, Possuir" in the sense of own something.