xml file opening error

string[] Filelist = Directory.GetFiles(this.XML_FPath_Textbox.Text.ToString());
            try
            {
                foreach (string file in Filelist)
                {
                    Application.DoEvents();
                    XmlDocument xmldoc = new XmlDocument();
                    XmlNodeList xmlnode;
                    FileStream fs = new FileStream(file, FileMode.Open, FileAccess.Read);
                    xmldoc.Load(fs);
                    xmlnode = xmldoc.GetElementsByTagName("Source");
                    foreach (XmlNode n in xmlnode)
                    {
                       string token = n.InnerText.ToString().Replace(@"\\az77-fs1\epic_rel\", "");
                       string Destination_File_Name = Path.GetFileName(token);
                       string[] tokenaizer = token.ToString().Split('\\');
                       if (Regex.IsMatch(token, "names.dat", RegexOptions.IgnoreCase))
                       {
                           using (StreamWriter sw = new StreamWriter("Analyzer.txt",true))
                           {
                               token = Regex.Replace(token, @"THIRD_PARTY\\", "", RegexOptions.IgnoreCase);
                               token = Regex.Replace(token,@"platforms\\","",RegexOptions.IgnoreCase);
                               token = Regex.Replace(token,@"productsoftware\\","",RegexOptions.IgnoreCase);
                               sw.WriteLine(token.ToString());
                           }
                       }
                    }
                }

                string[] lines = File.ReadAllLines(@"Analyzer.txt");
                lines = lines.GroupBy(x => x).Where(g => g.Count() > 1).Select(g => g.Key).ToArray();
                File.WriteAllLines(@"AnalyzerFINAL.txt", lines);
                Process.Start("notepad.exe", "AnalyzerFINAL.txt");
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message.ToString(), "Analyzer", MessageBoxButtons.OK, MessageBoxIcon.Warning);
            }