If you have no intention to edit the XLSX file, and you just want to view it, you can install the free Microsoft Office Excel Viewer at the link below. It supports printing and
copying data out of the XLSX file too, which may be all you need to do. https://www.microsoft.com/en-us/download/details.aspx?id=10
I had to try twice to get this sorted, but it works.
Thanks to Joseph ME for the info on Open Office. I need to switch. I attempted to update to Word2010 some time ago but it wrecked the formatting of files created in Word2002.
A Googled answer stated the most recent release of Microsoft Excel (2016, I think) reads/saves files in a different format than previous versions. Amazon is apparently "upgrading" to accommodate the new software release. I have not tried one of the conversion programs. If you have a friend that has the new version, they will probably be able to open the new format then, using "Save As", save the file to the old .xls format and send the file back to you. Or you can spend $150 and get the new release. Perhaps Amazon could consider preparing their reports in PDF format since most everybody can open a PDF file.