Gson cannot be resolved to a type error randomly started appearing

public static Partita carica(int id) {
        Gson gson = new Gson();
        return gson.fromJson(Utili.leggiFileJson("partite", Integer.toString(id)), Partita.class);
    }

public static Partita carica(int id) {
        Gson gson = new Gson();
        return gson.fromJson(Utili.leggiFileJson("partite", Integer.toString(id)), Partita.class);
    }

public static void main(String[] args) {
                Gson gson = new Gson();
                Partita p = gson.fromJson(Utili.leggiFileJson("partite", Integer.toString(25066)), Partita.class);
        }

public static void main(String[] args) {
                Gson gson = new Gson();
                Partita p = gson.fromJson(Utili.leggiFileJson("partite", Integer.toString(25066)), Partita.class);
        }