I figured out why the the attempt to load the file fails.
It contains a steam named “Book” which related to Biff5 - office 95 format.
While a Biff8 (office 97-2003) related stream for a workbook is called Workbook.
This is very hard to diagnose, is it possible to make the “This file’s format is not supported or you don’t specify a correct format.” message more verbose?
Like “Encountered unsupported stream \Book.” or something like that?
Good to know that you have sorted out your issue now.
Well, you may detect file format type prior loading via Workbook object to handle it accordingly (so, Aspose.Cells should not open the file). See the following sample code for your reference
We recommend you to kindly try upgrading to and use latest version of the product which includes support for older BIFF7 (Excel 95/5.0 - 2003 Workbook) formats with enhancements now:
Also, see the document for supported input and output file formats by Aspose.Cells: