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.