I insert a image to the sheet, and transform sheet to datauri format. I get a error message.
function SaveElnFile(e) {
        var spreadSheet = GetSpreadsheet("ElnMain");
        var sheet = spreadSheet.activeSheet();
        spreadSheet.bind("excelExport", function (e) {
            var fileName = "ElnTemplate/" + GetDateTimeString() + ".xlsx";
            e.workbook.fileName = fileName;
            var workbook = new kendo.ooxml.Workbook({
                sheets: e.workbook.sheets
            });
            workbook.toDataURLAsync().then(function (dataURL) {
                xxxxxx....
            });
                e.preventDefault();
        });
        spreadSheet.saveAsExcel();
    }
