Program.cs

namespace q34058426
{
    class Program
    {
        static void Main(string[] args)
        {
            try
            {
                // COPY FROM https://github.com/knightmeister/RazorEngineIssue/blob/master/Global.asax.cs (line 25-38)
                // init razor
                var razor = IsolatedRazorEngineService.Create(() => createRazorSandbox());

                // create the content model
                ContentModel cm = new ContentModel();
                cm.Html = "<h1>html here</h1>";
                cm.Title = "Title";
                var authors = new List<UserDetail>();
                authors.Add(new UserDetail() { EmailAddress = "hello@world.com", Name = "Test" });
                cm.History.Authors = authors;

                // run the transform
                // EDIT: Use another template to ensure we really can render user details from the authors list
                //string template = "@Model.Html";
                string template = "@Model.History.Authors[0].EmailAddress";

                // EDIT: Ditch RazorDynamicObject
                // string result = razor.RunCompile(template, "name", typeof(ContentModel), RazorDynamicObject.Create(cm));
                string result = razor.RunCompile(template, "name", typeof(ContentModel), cm);

                // END COPY
                Console.WriteLine(result);
            }
            catch (Exception error)
            {
                Console.WriteLine(error);
            }

            Console.ReadKey(true);
        }

        // COPY FROM https://github.com/knightmeister/RazorEngineIssue/blob/master/Global.asax.cs (line 43-65)
        private static AppDomain createRazorSandbox()
        {
            System.Security.Policy.Evidence ev = new System.Security.Policy.Evidence();
            ev.AddHostEvidence(new System.Security.Policy.Zone(SecurityZone.Internet));
            PermissionSet permSet = SecurityManager.GetStandardSandbox(ev);
            // We have to load ourself with full trust
            System.Security.Policy.StrongName razorEngineAssembly = typeof(RazorEngineService).Assembly.Evidence.GetHostEvidence<System.Security.Policy.StrongName>();
            // We have to load Razor with full trust (so all methods are SecurityCritical)
            // This is because we apply AllowPartiallyTrustedCallers to RazorEngine, because
            // We need the untrusted (transparent) code to be able to inherit TemplateBase.
            // Because in the normal environment/appdomain we run as full trust and the Razor assembly has no security attributes
            // it will be completely SecurityCritical. 
            // This means we have to mark a lot of our members SecurityCritical (which is fine).
            // However in the sandbox domain we have partial trust and because razor has no Security attributes that means the
            // code will be transparent (this is where we get a lot of exceptions, because we now have different security attributes)
            // To work around this we give Razor full trust in the sandbox as well.
            System.Security.Policy.StrongName razorAssembly = typeof(RazorTemplateEngine).Assembly.Evidence.GetHostEvidence<System.Security.Policy.StrongName>();
            AppDomainSetup adSetup = new AppDomainSetup();
            adSetup.ApplicationBase = AppDomain.CurrentDomain.SetupInformation.ApplicationBase;
            AppDomain newDomain = AppDomain.CreateDomain("Sandbox", null, adSetup, permSet, razorEngineAssembly, razorAssembly);

            return newDomain;
        }
    }

    // COPY FROM: https://github.com/knightmeister/RazorEngineIssue/blob/master/Models/Models.cs

    [Serializable] // EDIT: Mark as serializable
    public class ContentModel
    {
        public string Html { get; set; }
        public string Title { get; set; }
        public EditHistory History { get; set; }

        public ContentModel()
        {
            History = new EditHistory();
        }
    }

    [Serializable] // EDIT: Mark as serializable
    public class EditHistory
    {
        // EDIT: Changed from collection to list so that we can use indexer in template.
        public IReadOnlyList<UserDetail> Authors { get; set; }

        public EditHistory()
        {
            Authors = new List<UserDetail>();
        }
    }

    [Serializable] // EDIT: Mark as serializable
    public class UserDetail
    {
        public string Name { get; set; }
        public string EmailAddress { get; set; }
    }
}