Corrupted workbook recovery

The first thing I'd recommend is making a copy of the workbook and leaving the original untouched. If it's stored on a network drive, USB stick, or a cloud-synced folder (such as OneDrive), copy it to your local drive before trying any recovery steps.

Then in Excel, go to File > Open > Browse, select the workbook, click the arrow next to Open, and choose Open and Repair. Try Repair first. If that doesn't work, repeat the process and choose Extract Data, which may recover your formulas and values even if the workbook can't be fully repaired.

If the file is stored in OneDrive or SharePoint, check its Version History. Restoring a version from before the corruption occurred is often the quickest and most reliable solution.

If those options don't help, don't keep opening and saving the damaged file. Instead, check for:

An AutoRecover version.

A backup or previous version (for example, File History or your organization's backup system).

If you can share (without sensitive data):

the exact error message,

your Excel version,

the file type (.xlsx, .xlsm, etc.),

where the file is stored (local drive, network, OneDrive, USB, etc.),

and OS system,

I can try to suggest the most appropriate recovery approach.

Good luck—I hope you're able to recover it.