There could be multiple reasons for this error.
1. jQuery DataTables library is missing.
2. jQuery library is loaded after jQuery DataTables.
3. Multiple versions of jQuery library is loaded.
Plain text1<br><script src = "http://cdn.datatables.net/1.10.18/js/jquery.dataTables.min.js" defer ></script>
//Just add defer at the end of this script
