Cannot read property '_buttons' of undefined

All Buttons Working Fine, Except Excel Export ?Please Help.

library includes:

require.config({
                waitSeconds : 30,
                paths: {
                    "datatables.net": "../datatable/dataTables.min",
                     "dataTables": '../datatable/DataTables-1.10.18/js/jquery.dataTables.min',
                    "datatables.net-buttons": "../datatable/dataTables.buttons.min",
                    "datatables.net-html5": "../datatable/buttons.html5.min",
                    "datatables.net-print": "../datatable/buttons.print.min",
                    "datatables.net-Select": "../datatable/Select-1.2.6/js/dataTables.select.min",
                    "datatables.net-flash": "../datatable/Buttons-1.5.2/js/buttons.flash.min",
                    "datatables.net-jszip": "../datatable/JSZip-2.5.0/jszip.min",
                    "datatables.net-pdfmake": "https://cdnjs.cloudflare.com/ajax/libs/pdfmake/0.1.36/pdfmake.min",
                    //"datatables.net-pdfmake": "..datatable/pdfmake-0.1.36/pdfmake.min",
                    "datatables.net-vfs_fonts": "https://cdnjs.cloudflare.com/ajax/libs/pdfmake/0.1.36/vfs_fonts",
                    //"datatables.net-vfs_fonts": "../datatable/pdfmake-0.1.36/vfs_fonts",
                    'datetimepicker': '../Scripts/bootstrap-datetimepicker.min',
                    jquery: '../Script/js/jquery-3.3.1.min',
                    pnp: '../Script/pnp/pnpjs.es5.umd.bundle.min',
                    promise: '../Script/pnp/es6-promise.min',
                    fetch: '../Script/pnp/fetch',
                    polyfill: '../Scripts/polyfill.min',
                    RateCardDashboard: '../Scripts/RateCardDashboard',
                    bootstrapValidator: '../Scripts/bootstrapValidator',
                    dataTables: '../datatable/DataTables-1.10.18/js/jquery.dataTables.min',
                    bootstrapmin: '../Scripts/bootstrap.min',
                    jqueryconfirm: '../Content/jquery-confirm.min',
                    xlsx: '../Content/xlsx.full.min'
                },
                shim: {
                    'pnp': {
                        deps: ['promise', 'fetch', 'polyfill']
                    },
                    'RateCardDashboard': {
                        deps: ['pnp','bootstrapValidator']
                    },
                    "datatables.net": {
                        deps: ['jquery','jqueryconfirm', "bootstrapmin"]
                    }
                }
            });
            require(['xlsx',"dataTables", 'datatables.net-buttons',"datatables.net-flash", "datatables.net-jszip", "datatables.net-pdfmake", "datatables.net-vfs_fonts", "datatables.net-html5", 'datatables.net-print', "RateCardDashboard"], function (datatables, botton, html5, jszip, pdfmake) {
                    window.JSZip = jszip;
                    window.pdfmake = pdfmake;
                });

Datatable Initialize:

$('#RateCardGrid').DataTable({
                   orderCellsTop: true,
                   autoWidth: false,
                   fixedColumns: true,
                   dom: 'Bfltip',
                   "columnDefs": [{
                       "orderable": false,
                       "targets": [3, 11]
                   }, {
                       "targets": [12],
                       "visible": false,
                       "searchable": false
                   }, {
                       "targets": [13],
                       "visible": false,
                       "searchable": false
                   }
                   //    , {
                   //    "targets": [14],
                   //    "visible": false,
                   //    "searchable": false
                   //}
                       ]
                   //,
                   //"orderFixed": [0, 'asc']
               });

Start with the RequireJS configuration and the DataTable initialization for #RateCardGrid, then reproduce the Excel export failure while checking the module dependencies and require callback. The issue is done when Excel export works without the “_buttons” undefined error; no test file is provided, so verify the behavior manually.