{"Type mismatch. (Exception from HRESULT: 0x80020005 (DISP_E_TYPEMISMATCH))"}

private void SetWordDocument()
{
string strFileName =
CleanUp(LabelFirstName.Text + "_" + LabelLastName.Text + "_" + DateTime.Now.ToString("yyyy-MM-dd") +
"." + DropDownListDownloadCv0.SelectedItem.Text);

object fileStream =
new FileStream(Server.MapPath("~/Upload/") +
strFileName,FileMode.Create);


using (var db = new knowitCVdbEntities())
{
var theEmpl = (from p in db.EMPLOYEES
where p.username == strUserName
select p).FirstOrDefault();



if (theEmpl != null)
{

object missing = Missing.Value;
object start1 = 0;


var wordApp = new ApplicationClass();


Microsoft.Office.Interop.Word.Document myDoc = wordApp.Documents.Add(ref missing, ref missing,
ref missing, ref missing);

Range rng = myDoc.Range(ref start1, ref missing);

try
{

const char newLine = (char) 11;

myDoc.SaveAs(ref fileStream,
ref missing, ref missing, ref missing, ref missing, ref missing,
ref missing, ref missing, ref missing, ref missing, ref missing,
ref missing,
ref missing,
ref missing, ref missing, ref missing);


here i have some textboxes
mydoc.Save();

<pre lang="cs">Response.ContentType = "Application/msword";
Response.AppendHeader("Content-Disposition", "attachment; filename=" + strFileName);
Response.TransmitFile(Server.MapPath("~/Upload/") + strFileName);
Response.End();</pre>

dont get it to work on Microsoft.Office.Interop.Word.Document myDoc = wordApp.Documents.Add(ref missing, ref missing, ref missing, ref missing); here i added ref fileStream also , but then i get same error on that place ?