Object reference not set to an instance of an object.
at System.Data.DataTable.NewRow(Int32 record)
at System.Data.DataRowCollection.AddWithColumnEvents(Object[] values)
at System.Data.XmlDataLoader.LoadTable(DataTable table, Boolean isNested)
at System.Data.XmlDataLoader.LoadData(XmlReader reader)
at System.Data.DataSet.ReadXml(XmlReader reader, XmlReadMode mode, Boolean denyResolving)
at System.Data.DataSet.ReadXml(String fileName, XmlReadMode mode)
It occurs when multiple calls to read xml files.