C#

private void InitIdentityColumn()
{
        if (this.dt.Columns.Contains("rowID"))
        {
                     this.dt.Columns.Remove("rowID");
        }
         
         DataColumn dc = new DataColumn("rowID");
         this.dt.Columns.Add(dc);

         int i = 0;
         foreach (DataRow row in this.dt.Rows)
         {
                    i += 1;
                    row["rowID"] = i;
         } 
}

FrmCategory frm = new FrmCategory(false, false);
DsStack.CategoriesRow newRow = this.dt.NewCategoriesRow();
Session.SaveInSession("newCategory", newRow);
if (frm.ShowDialog() == DialogResult.OK)
{   
    newRow = Session.LoadFromSession("newCategory") as DsStack.CategoriesRow;   
    this.dt.Rows.Add(newRow);   
    this.adapter.Update(this.dt); // error occured in this line
}