Delete the FileDownloadDialog.aspx and FileUploadDialog.aspx files from wwwroot\aspnet_client\ESRI\WebADF\WebForms after making backup copies- In an application that requires one of these dialogs, copy the dialog to a folder called WebForms in the application’s root foldero FileDownloadDialog is used to save Result files on long-running asynchronous GP tasks so that the results may be checked later.o FileUploadDialog is used to upload parameters to GP tasks that have an input GPDataFile parameter.