I have the following surface controller. Which gets a null exception on the follwoing line. When running in VS debug mode i get "Object reference not set to an instance of an object."

 var sendEmailsFrom = homeNode.GetPropertyValue("contactEmailFrom") ?? "xxx@xxx.com";

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Web.Hosting;
using System.Web.Mvc;
using System.Xml;
using Umbraco.Core.Models;
using Umbraco.Web;
using cericoumbraco.Models;

namespace cericoumbraco.Controllers
{
    public class ContactController : Umbraco.Web.Mvc.SurfaceController
    {
        [ChildActionOnly]
        public ActionResult ContactForm()
        {
            var model = new ContactModel();

            //Initialize model however you want

            //In case you need to access the current node
            var currentNode = Umbraco.TypedContent(UmbracoContext.PageId.GetValueOrDefault());

            //In case you need to access the home node
            var homeNode = currentNode.AncestorsOrSelf(0).FirstOrDefault();

            return PartialView("ContactForm", model);
        }


        [HttpPost]
        public ActionResult ContactForm(ContactModel model)
        {
            // server validation here
            // TempData["ErrorMessage"] = "Error processing field ...";

            if (ModelState.IsValid)
            {
                var currentNode = Umbraco.TypedContent(UmbracoContext.PageId.GetValueOrDefault());


                var homeNode = currentNode.AncestorsOrSelf(0).FirstOrDefault();


                var sendEmailsFrom = homeNode.GetPropertyValue("contactEmailFrom") ?? "xxx@xxx.com";
                var sendEmailsTo = homeNode.GetPropertyValue("contactEmailTo") ?? "xxx@xxx.com";


                var body = String.Format("There has been an enquiry from the xxx website 
 
 Name:  {0} (@ {1}) 
 Email: {2}
 Tel: {3}

  Message: {4}", model.FullName, model.Company, model.Email, model.Telephone, model.Message);
                var subject = "XXX website enquiry";


                try
                {
                    umbraco.library.SendMail(sendEmailsFrom, sendEmailsTo, subject, body, true);

                    TempData["InfoMessage"] = "Your message has been successfully sent and we will be in touch soon...";

                    // Clear all the form fields
                    ModelState.Clear();
                    model.FullName = string.Empty;
                    model.Company = string.Empty;
                    model.Telephone = string.Empty;
                    model.Email = string.Empty;
                    model.Message = string.Empty;


                    //redirect to current page to clear the form
                    return RedirectToCurrentUmbracoPage();
                }
                catch (Exception ex)
                {
                    TempData["ErrorMessage"] = "There was an issue sending your message: " + ex.Message + ex.StackTrace;
                }
            }


            return CurrentUmbracoPage();

        }
    }
}