One driveの同期に

Hello, thank you for reaching out to Microsoft Q&A.

Could you please share the exact error message or error code you receive when syncing your OneDrive files on your Mac?

Also, have you downloaded the OneDrive app from the App Store? If yes, to enable backup of your important folders (Desktop and Documents) on macOS, you will need to download the standalone app:

1. Download the standalone OneDrive app from the link below: https://go.microsoft.com/fwlink/?linkid=823060
2. Uninstall any previously installed version of the OneDrive app.
3. Install the standalone version you just downloaded.
4. Your macOS device must have Full Disk Access enabled. Go to System Settings > Privacy & Security > Full Disk Access, then add OneDrive to the list of applications.

If you are still experiencing sync issues, you can try resetting OneDrive:

1. Select the OneDrive cloud icon in the top tray, then select Preferences > Pause > Quit OneDrive.
2. Find OneDrive in your Applications folder.
3. Control-click OneDrive and select Show Package Contents.
4. Navigate to the Contents > Resources folder.
5. Double-click ResetOneDriveApp.command (or ResetOneDriveAppStandalone.command, if you're using the standalone app).
6. Start OneDrive and finish the setup process.

Reference:

OneDrive をリセットする

Let me know if you still need more help.