Excel file problem

When I download an Excel file from iCloud (on my Mac laptop), I get a message saying: "We found a problem with some content in the file. Do you want us to try to recover as much as possible? Click "yes" if you trust the source of this workbook." I click yes, but the file then opens in a corrupted or unusable state. How can I retrieve the original file as it was before? Please recommend a solution.