Sharepoint cannot open .xls files

[petargavrilov]

Hello, I've got an organisation-wide issue where Sharepoint cannot open some (not all) .xls files I've uploaded to a directory. This issue seems to occur only in Sharepoint & I am able to open the files (before uploading them to Sharepoint) on Windows 10 without any issues. 

I've tried to circumvent this for my organisation and downloading the files results in a corrupt extension or file which cannot be opened either way.

My suspicion is that during the upload process something corrupts the extention but I cannot get down to finding a solution. Help is greatly appreciated!

[#2]

Hi there,
Excel Online doesn't support .XLS files, you should save the files in .XLSX format before uploading to SharePoint Online.

Have you tried creating a OneDrive Shortcut to the Document Library and then opening the files from Windows Explorer?

[#3]

When I am downloading the file I have no choice on which format to save it since I am downloading the files from an accounting platform and the format is preset. I've also tried to change the extension of the files on my computer and when I upload them they're still being read as .xls instead of . xlsx.

[#4]

Unfortunately, it will be the file being generated by the accounting platform that is the issue. Renaming the file won't resolve the issue because it doesn't change the file format.