Hi we are using your product for our app.
When I am reading from .xls file throws Exception: This is not a structured storage file.
LoadOptions options = new LoadOptions(LoadFormat.Excel97To2003);
var excleFile = new FileStream(path, FileMode.Open);
Workbook workbook = new Workbook(excleFile, options )
I tested your scenario/ case a bit using your template file with Aspose.Cells for .NET v19.1 (please try it). I found no issue or exception using your sample code. It works fine. Also, I found your so called XLS file is actually an XLSX file, so you may also try to change the line of your code:
i.e.,
LoadOptions options = new LoadOptions(LoadFormat.Excel97To2003);
with:
LoadOptions options = new LoadOptions(LoadFormat.Auto);
If you still find the issue with v19.1, do let us know with details and sample code, we will check it soon.