A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
Hi Alan,
If you just upload the affected files onto a SharePoint site collection, I’d like to confirm if the files are originally an HTML or XLA file but with an .XLS file extension. If yes, you may be unable to open the Excel files. You can refer to the workaround in https://support.microsoft.com/en-us/kb/3181507 to see the result.
Moreover, I’d like to know the version number of your Excel 2016. Could you check it via File>Account and stay on the page, and then capture a screenshot for us? If the version is lower than 6965.2053 or later, I suggest you change the channel of Office 2016 and update to the version mentioned to give a shot.
If the affected files are created via previous Excel clients, create the same file via Excel 2016 to check the outcome.
Please let us know your updates at your convenience.
Thanks,
Cliff