Html.DropDownList selected value not working using ViewBag

The problem may also be the name, see here.

In the Controller

ViewBag.PersonList= new SelectList(db.Person, "Id", "Name", p.PersonId); 

In the View

@Html.DropDownList("PersonList",(SelectList)ViewBag.PersonList )

This will not work, you have to change the name, so it's not the same.

@Html.DropDownList("PersonList123",(SelectList)ViewBag.PersonList )

So change yearDropDown and it Will Work for you.

Best regards Christian Lyck.

Unobtrusive validation doesn't work with Ajax.BeginForm

You need to add those 2 files in you Partial View even if it is already in the Shared/_Layout.cshtml:

<script src="@Url.Content("~/Scripts/jquery.validate.min.js")" type="text/javascript"></script>
<script src="@Url.Content("~/Scripts/jquery.validate.unobtrusive.js")" type="text/javascript"></script>

Or place this in your Partial:

<script type="text/javascript" language=javascript>