I just lost several days of work in Excel following a Microsoft excel update syncing problem in OneDrive

Hi Naomi, I understand how frustrating that can be. I look forward to helping you:

Retrieve a previous version from OneDrive Web

1. Go to your OneDrive web and log in with your account.
2. Navigate to where the Spreadsheet.xlsx file is saved.
3. Right-click on the file and select Version History.
4. A list of previous versions will open. Find one that has a date and time before the error message.
5. Click Restore to replace the current file, or Open File to check first.

Recovering a previous version from excel desktop application

1. Open Excel and select File > Info.
2. If the file was saved to OneDrive with AutoSave, you should see a section that says Versions or Manage workbook.

Browse the previous versions and choose Restore the one you think contains all your sheets.

In general, I don't really like to work with synchronized files from desktop, it is very common this kind of failures. Since a few months ago I am changing my way of working, I share it with you.

First I look for the file I have in OneDrive or Sharepoint and from there, I open it in desktop application. This is 100% guaranteed synchronization with no possibility of errors or failures.

If you find my answer helpful, please remember to mark it as a reply. This way, other user friends will know that the answer to your question in the title was answered here and they can quickly find the answer to their same question.

Thank you very much.