Fix OneDrive Files Appearing Corrupt After Upgrading to macOS Big Sur
Question details
Users are experiencing severe file corruption issues with Microsoft 365 documents and other files synchronized through OneDrive after upgrading their Mac operating system.
- Product
- Microsoft OneDrive
- Device & OS
- macOS Big Sur
- Scenario
- Upgrading a Mac operating system from macOS Catalina to macOS Big Sur while using OneDrive for file synchronization.
- Observed behavior
- Approximately 97% of local OneDrive files become unreadable or appear corrupt, whereas similar files stored locally or on iCloud Drive remain unaffected.
Do not delete, move, or replace any of the affected local files on your Mac yet. Log in to the OneDrive web portal first to check if the cloud versions of your files are intact.
Check OneDrive Online and Restore Version History
Verify the integrity of your files via the cloud interface and restore them to a previous version if the cloud copies are also showing signs of corruption.
Often, the corruption is isolated to the local synchronization cache on macOS Big Sur. The actual files safely hosted on Microsoft's servers may still be perfectly intact.
Open your web browser, navigate to the official OneDrive website, and sign in with your Microsoft account credentials.
Locate the Microsoft 365 documents that appear corrupt on your Mac. Click to open them directly in the browser to see if they load correctly.
If the online files are also corrupted, right-click the file, select 'Version history', and choose a version dated before your macOS Big Sur upgrade to restore.
Contact Microsoft Virtual Agent Support
Reach out to official OneDrive support to investigate the account-level synchronization issue caused by the macOS upgrade.
Try WPS Office for a More Reliable Mac Experience
If OneDrive and Microsoft 365 sync issues are disrupting your workflow on macOS Big Sur, consider switching to WPS Office. It provides a lightweight, fast, and highly compatible workspace for all your document needs without the heavy synchronization overhead.
- 1. Download for Mac: Visit the WPS Office website and download the macOS installer.
- 2. Install the application: Open the downloaded package and drag the WPS Office icon into your Applications folder.
- 3. Open your recovered files: Launch WPS Office and directly open your restored Word, Excel, or PowerPoint documents to resume your work.
Frequently Asked Questions
Why did my OneDrive files become corrupt after upgrading to Big Sur?
Major macOS operating system upgrades can sometimes disrupt the background synchronization cache of OneDrive. This breaks the local file pointers on your Mac, making the documents appear as corrupted files when you attempt to open them locally.
Are my corrupted OneDrive files permanently lost?
Not necessarily. In most cases, the corruption only affects the local cached versions on your Mac. The original files usually remain safe in the cloud and can be accessed or restored via the OneDrive website.
Does this upgrade issue affect iCloud Drive as well?
Based on user reports, this specific corruption issue seems isolated to Microsoft OneDrive during the Catalina to Big Sur transition. Files stored natively on iCloud Drive typically remain unaffected and perfectly intact.
Should I uninstall and reinstall OneDrive on my Mac?
Before attempting to uninstall or unsync OneDrive, you must verify that your files are intact on the OneDrive website. Reinstalling the app clears local caches and could complicate recovery if the cloud files aren't backed up properly first.
