We use the code below to get NestedContent, on v7 was working fine, but when we tried to migrate to v8 and changed the IPublishedContent with IPublishedElement, we get an error:

System.MissingMethodException: 'Constructor on type 'Models.Fields.Section' not found.

 protected List<T> GetNestedList<T>(string alias)
    {
        Type type = typeof(T);
        List<T> list = new List<T>();

        IPublishedElement singleResult = Get<IPublishedElement>(alias);

        if (singleResult != null)
        {
            list.Add((T)Activator.CreateInstance(type, singleResult));
        }

        IEnumerable<IPublishedElement> multipleResults = Get<IEnumerable<IPublishedElement>>(alias);

        if (multipleResults != null)
        {
            foreach (IPublishedElement result in multipleResults)
            {
                list.Add((T)Activator.CreateInstance(type, result));
            }
        }

        return list;
 }

The only change we did to the code was replacing IPublishedContent -> IPublishedElement.

We really need help on this.