- Close Excel, then reopen it and retry saving the file
- Check if the file is marked “Read‑Only” or stored in a protected location (e.g., OneDrive, network share); try saving it elsewhere
- Disable all Excel add‑ins via File → Options → Add‑Ins → Go… then uncheck everything and restart Excel
- Repair Office through Control Panel → Programs → Microsoft Office → Change → Repair
- Open Excel in Safe Mode (
excel.exe /safe
) and test saving—if it works, the issue is likely with one of the add-ins or customizations - Ensure Excel and Windows are fully patched via Windows Update, then reboot
For a step‑by‑step walkthrough and advanced troubleshooting, visit this Excel not saving changes fix guide.