[HttpGet("/api/[controller]/[action]/{applicationId}/")]
public async Task<IActionResult> GetProducts(int applicationId)
{
    //return List<MyModel>
    var products = await this._mortgageApplicationService.GetMortgageApplicationProducts(applicationId);
    var json = JsonConvert.SerializeObject(products);
    return Ok(json);
}

function getReportData() {
    var applicationId = $("#MortgageApplicationId").val();
    var url = "/api/MortgageStageProductsApi/GetProducts/" + applicationId;

    //This does NOT work
    $("#productGrid").kendoGrid({
        dataSource: {
            transport: {
                read: url,
                dataType: "json"
            },
            schema: {
                model: {
                    id: "Id",
                    fields: {
                        Id: { type: "number" },
                        ProductProvider: { type: "string" },
                        ProductTypeName: { type: "string" },
                        MortgageExpiry: { type: "string" }
                    }
                }
            },
            pageSize: 20,
            serverPaging: false,
            serverFiltering: false,
            serverSorting: false
        },
        filterable: true,
        sortable: true,
        pageable: false,
        columns: [{
            field: "Id",
            filterable: false
        }, {
            field: "ProductProvider",
            title: "Provider"
        }, {
            field: "ProductTypeName",
            title: "Product Type"
        }, {
            field: "MortgageExpiry",
            title: "Expiry"
        }
        ]
    });


    //This works using json object created using the same json returned
    var products = [
        {
            Id: 1,
            MortgageApplicationId: 2171,
            ProductProvider: "Ulster Bank",
            MortgageTermYears: 5,
            MortgageTermMonths: 10,
            MortgageRepaymentType: 1,
            ProductTypeId: 1,
            ProductTypeName: "Fixed",
            MortgageProductTermYears: 5,
            MortgageExpiry: "2025-01-21T00:00:00",
            MortgageLenderRate: null,
            MortgageAdviceFee: 120,
            ProductBrokerCommissionPercentage: 10,
            ProductBrokerCommissionFlatFee: null,
            DocumentsUploadedList: []
        },
        {
            Id: 2,
            MortgageApplicationId: 2171,
            ProductProvider: "Ulster Bank",
            MortgageTermYears: 5,
            MortgageTermMonths: 10,
            MortgageRepaymentType: 1,
            ProductTypeId: 1,
            ProductTypeName: "Fixed",
            MortgageProductTermYears: 5,
            MortgageExpiry: "2025-01-21T00:00:00",
            MortgageLenderRate: null,
            MortgageAdviceFee: 120,
            ProductBrokerCommissionPercentage: 10,
            ProductBrokerCommissionFlatFee: null,
            DocumentsUploadedList: []
        }
    ];

    $("#productGrid1").kendoGrid({
        dataSource: {
            data: products,
            schema: {
                model: {
                    id: "Id",
                    fields: {
                        Id: { type: "number" },
                        ProductProvider: { type: "string" },
                        ProductTypeName: { type: "string" },
                        MortgageExpiry: { type: "string" }
                    }
                }
            },
            pageSize: 20,
            serverPaging: false,
            serverFiltering: false,
            serverSorting: false
        },
        filterable: true,
        sortable: true,
        pageable: false,
        columns: [{
            field: "Id",
            filterable: false
        }, {
            field: "ProductProvider",
            title: "Provider"
        }, {
            field: "ProductTypeName",
            title: "Product Type"
        }, {
            field: "MortgageExpiry",
            title: "Expiry"
        }
        ]
    });
}

var filemanagerNS = kendo.ui.filemanager;
        filemanagerNS.commands.MyCustomCommand = filemanagerNS.FileManagerCommand.extend({
          exec: function(){
                 var FileIDs = Array();
                 var i = $('#filemanager').getKendoFileManager().getSelected();
                 $(i).each(function(){
                     if (!this.isDirectory)
                        FileIDs.push(this.ID);
                 });

                if (FileIDs.length > 0) {
                    // we'd call up our modal here populated with some kind of tag manager
                    $.post( "/Tags", { "FileIDs": FileIDs }, function( data ) {
                        $("#frmmodal").html(data).data("kendoWindow").open();
                    });
                 }
          }
        });

Uncaught TypeError: n.filemanager.commands[t] is not a constructor
    at init.executeCommand (kendo.all.js:318819:21)
    at init.trigger (kendo.all.js:318819:21)
    at init.action (kendo.all.js:318819:21)
    at init._onSelect (kendo.all.js:318819:21)
    at init.trigger (kendo.all.js:318819:21)
    at init._triggerEvent (kendo.all.js:318819:21)
    at init._triggerSelect (kendo.all.js:318819:21)
    at init._click (kendo.all.js:318819:21)
    at HTMLUListElement.dispatch (jquery.min.js:3:12445)
    at r.handle (jquery.min.js:3:9174)