System.Data.SqlClient.SqlException: SQL Server Internal Error. Text manager cannot continue with current statement.

Question

 SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["Safa"].ConnectionString);

    string branchid = "";
    protected void Page_Load(object sender, EventArgs e)
    {
      branchid= Session["branchid"].ToString();
        if (IsPostBack == false)
        {
      Image1.ImageUrl = "left1.ashx?BranchId=" + branchid;
      Image2.ImageUrl = "left1old.ashx?BranchId=" + branchid;
            


  }

 protected void Button1_Click(object sender, EventArgs e)
    {
// update code
        SqlCommand cmdupdate = new SqlCommand("left1update", con);
        cmdupdate.CommandType = CommandType.StoredProcedure;
        con.Open();
        cmdupdate.Parameters.AddWithValue("@BranchId", branchid);

        if ( FileUpload1.HasFile)
        {
            FileInfo left1info = new FileInfo(  FileUpload1.PostedFile.FileName.Trim());
            byte[] left1content = new byte[left1info.Length];
            FileStream left1stream = left1info.OpenRead();
            left1stream.Read(left1content, 0, left1content.Length);
            left1stream.Close();
           cmdupdate.Parameters.AddWithValue("@imgleft1",left1content); 
}
 cmdupdate.Parameters.AddWithValue("@notel1",txtnotes.Text);


        if(cmdupdate.ExecuteNonQuery()!=0)
        {
        Functions.ShowAlertMessage("Updated.....");
        txtnotes.Text = "";
        System.Threading.Thread.Sleep(2000);
        Image1.ImageUrl = "left1.ashx?BranchId=" + Session["branchid"].ToString();
        Image2.ImageUrl = "left1old.ashx?BranchId=" + Session["branchid"].ToString();
        
        }

 
procedure iam using

create procedure left1update(@BranchId nvarchar(50),@imgleft1 image, @notel1 nvarchar(200))
as
update tblImages set imgleft1old= CONVERT( image,imgleft1)
,imgleft1=@imgleft1 ,notel1=@notel1 where (BranchId=@BranchId)


GO

when iam clicking the button my current image should store in imgleft1old field and the newly browse one should store in imgleft1 field

but it giving error
System.Data.SqlClient.SqlException: SQL Server Internal Error. Text manager cannot continue with current statement.



can you correct my code which helps me