Why is POST action losing model values?

I have a ViewModel which I'm trying to post back to save in the DB. While the ViewModel is getting the values set in the `//GET Create(int id)` it is losing some of them by the time it gets to the `//POST Create ()`. The `GoalLevel` and `GoalTitle` are being passed through OK, but the `ActorId` and `ProjectId` are being lost and even though the debugger is going through the `if (Model.State.IsValid)` block, the values that are going through aren't being saved to the DB. The redirect then falls over, because I've no longer got a valid `ProjectId` to pass to the URL. I'm sure it's something obvious if you know what you're doing! CONTROLLER ``` // GET: UseCases/Create public ActionResult Create(int id) { ViewBag.projectId = id; //Populate the ViewModel UserGoalsStepViewModel model = new UserGoalsStepViewModel() { ProjectId = id, ActorList = new SelectList(db.Actors.Where(a => a.projectID == id), "id", "Title"), }; return View(model); } // POST: UseCases/Create // To protect from overposting attacks, please enable the specific properties you want to bind to, for // more details see http://go.microsoft.com/fwlink/?LinkId=317598. [HttpPost] [ValidateAntiForgeryToken] public ActionResult Create([Bind(Include = "ProjectId,ActorId,GoalTitle,Level")] UserGoalsStepViewModel model) { if (ModelState.IsValid) { //Create a use case object to map to, which can then be saved in the DB UseCase uc = new UseCase(); uc.ProjectID = model.ProjectId; uc.ActorID = model.ActorId; uc.Level = (Level)model.Level; db.SaveChanges(); return RedirectToAction("Index", new { id = model.ProjectId }); } return View(model); } ``` ViewModel ``` public class UserGoalsStepViewModel { public enum GoalLevel { Summary, UserGoal, SubGoal, } public int ProjectId { get; set; } public int ActorId { get; set; } [DisplayName("Actor Title")] public SelectList ActorList { get; set; } [DisplayName("Goal Title")] public string GoalTitle { get; set; } public GoalLevel Level { get; set; } public UserGoalsStepViewModel () { } } ``` VIEW ``` @using (Html.BeginForm()) { @Html.AntiForgeryToken() <div class="form-horizontal"> <h4>UseCase</h4> <hr /> @Html.ValidationSummary(true, "", new { @class = "text-danger" }) <div class="form-group"> @Html.LabelFor(model => model.ActorList, htmlAttributes: new { @class = "control-label col-md-2" }) <div class="col-md-10"> @Html.DropDownListFor(model => model.ActorList, Model.ActorList, new { @class = "form-control" }) @Html.ValidationMessageFor(model => model.ActorList, "", new { @class = "text-danger" }) </div> </div> <div class="form-group"> @Html.LabelFor(model => model.GoalTitle, htmlAttributes: new { @class = "control-label col-md-2" }) <div class="col-md-10"> @Html.EditorFor(model => model.GoalTitle, new { htmlAttributes = new { @class = "form-control" } }) @Html.ValidationMessageFor(model => model.GoalTitle, "", new { @class = "text-danger" }) </div> </div> <div class="form-group"> @Html.LabelFor(model => model.Level, htmlAttributes: new { @class = "control-label col-md-2" }) <div class="col-md-10"> @Html.EnumDropDownListFor(model => model.Level, htmlAttributes: new { @class = "form-control" }) @Html.ValidationMessageFor(model => model.Level, "", new { @class = "text-danger" }) </div> </div> <div class="form-group"> <div class="col-md-offset-2 col-md-10"> <input type="submit" value="Create" class="btn btn-default" /> </div> </div> </div> } ``` UPDATED POST METHOD WHICH IS STILL GIVING AN ERROR AND NOT SAVING TO DB After amends, I'm now getting this error `Message=The INSERT statement conflicted with the FOREIGN KEY constraint "FK_dbo.UseCase_dbo.Actor_ActorID". The conflict occurred in database "JustSpecIt", table "dbo.Actor", column 'ID'` when attempting to save to DB. Here is relevant bit of updated POST method: ``` if (ModelState.IsValid) { //Create a use case object to map to, which can then be saved in the DB UseCase uc = new UseCase(); uc.ProjectID = model.ProjectId; uc.ActorID = model.ActorId; uc.Title = model.GoalTitle; uc.Level = (Level)model.Level; db.UseCases.Add(uc); db.SaveChanges(); return RedirectToAction("Index", new { id = model.ProjectId }); } ```