Fix the Excel Error – Data May Have Been Lost
This problem occurs when users attempt to access an Excel sheet prepared in a previous version of MS Excel. This error prevents access to all data contained in it.
This is a frustrating scenario, however there are methods to recover Excel file data.
Open and Repair Utility
Open your Excel app and go to the File tab.
Click on Open and Browse.

Locate for the file that has the error and click on it.
Click the drop-down button of Open and select Open and Repair.

Select Repair to recover workbook data
NOTE: If Repair is unavailable, select Extract Data. A repaired version of your file should open.