XML : XML System.UnauthorizedAccessException

When I tried to save Xml file to a specific folder in first saved is good because there's no existing xml file inside of it, but if I will save it again in the same folder same name the error will show ...

this is my example code to generate the xml file ....

   XMLPath = Path.Combine(TargetRFIFolder, filename);                    try                  {                      XmlWriter xmlWriter = XmlWriter.Create(XMLPath);                        xmlWriter.WriteStartDocument();                      xmlWriter.WriteStartElement("TeklaPartObject");                        foreach (ListViewItem item in lv_Tekla_object.Items)                      {                          xmlWriter.WriteStartElement("part");                          xmlWriter.WriteAttributeString("ID", item.Text);                          xmlWriter.WriteString(item.SubItems[1].Text);                          xmlWriter.WriteEndElement();                      }                      xmlWriter.WriteStartElement("label");                      xmlWriter.WriteString(Path.GetFileName(lv_Directories.SelectedItems[0].ToolTipText));                      xmlWriter.WriteEndElement();                      xmlWriter.WriteEndDocument();                      xmlWriter.Close();                      xmlWriter.Flush();                      File.SetAttributes(XMLPath, File.GetAttributes(XMLPath) | FileAttributes.Hidden);    

thanks for the help guys, regards