Spreadsheet component sometimes opens index.html instead of excel file Declined - Cannot Reproduce

Hi Team,

I have used spreadsheet component from syncfusion in react and used a controller from where I am calling workbook open method to open the excel file but i am getting an intermittent issue where component opens up index.html page in the spreadsheet instead of opening original excel file. Can you please check this?

Controller code - 

[HttpPost]

        public IActionResult Open(IFormCollection openRequest)

        {

            OpenRequest open = new OpenRequest();

            open.File = openRequest.Files[0];

            var strContent = Workbook.Open(open);

            return Content(strContent);

        }

React Code - 

 <React.Fragment>

                <div className='control-pane'>

                    <div className='control-section spreadsheet-control'>

<SpreadsheetComponent openUrl={window.location.origin + getSiteUrl('/api/ExcelViewer/Open')} beforeOpen={this.beforeOpen} allowOpen={true}

                            allowEditing={false} isProtected enableKeyboardShortcut={false}

                            ref={(ssObj) => { this.spreadsheet = ssObj }} created={this.onCreated.bind(this)} />

                    </div>

                </div>

            </React.Fragment>