A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
We appreciate your response. XLS is a file format used in older versions of Excel specifically Excel 97- Excel 2003 Workbook and Microsoft Excel 5.0/95 Workbook. When you open an XLS file in Excel 2016, it usually opens in Compatibility Mode which retains the original format for backward compatibility.
If this is not happening, it is possible that either the file is damaged or it includes special formatting that can only be run by Excel 2010.
We suggest that you try to save the file as an Excel Workbook (.xlsx). Please take note that when you save a file in another file format, some of its formattings won’t be transferred. Here’s an article that includes instructions and other details about saving a workbook in another file format.
If the issue persists, you can proceed with repairing your workbook by following the instructions in this link.
Let us know if you need additional assistance.