One Drive files locked when accessed via file explorer that are not locked when accessed through One Drive

Right-click each affected file in File Explorer and select Always keep on this device; after its icon becomes a solid green circle with a white check mark, retry the SharePoint upload or email attachment.

A blue-cloud file is only a placeholder in File Explorer until OneDrive downloads it. Marking it Always keep on this device creates a complete local copy, which can resolve failures when another application needs to upload or attach the physical file ^1^ ^2^.

Check the icon and use the matching action

• Blue cloud: Right-click → Always keep on this device. Wait for the solid green circle.
• Circular arrows or “Sync pending”: Select the blue OneDrive cloud in the taskbar and wait for synchronization to finish. If it remains stuck, select Help & Settings → Pause syncing, then Resume syncing ^3^.
• Red circle with a white X: Select the taskbar OneDrive icon and open the displayed error. This indicates that the item cannot sync ^4^.
• Gray circle with a horizontal bar: Your organization has blocked synchronization of that file type. Contact the Microsoft 365 administrator; downloading it repeatedly will not remove the policy ^4^.
• Chain/link on a folder: This identifies a shortcut to a shared folder, not a file lock ^4^.

If it is an actual padlock

If the affected files belong to a synced SharePoint document library, determine whether that library requires checkout. A library configured with Require Check Out, content approval, or restrictive draft-item settings can present synced files as read-only or locked in File Explorer.

1. Open the document library in SharePoint in a browser.
2. Select the file and choose Check out.
3. Edit the file, then Check in when finished.
4. If checkout should not be required, ask the site owner to review Library settings → More library settings → Versioning settings → Require Check Out and disable it only if organizational policy permits ^5^.

Do not change Windows permissions or the local read-only attribute for a SharePoint-enforced lock; those changes do not override library policy.

If OneDrive reports a local permission error

Use this branch only when the OneDrive activity center specifically says that OneDrive lacks permission to access the file:

1. Right-click the file → Properties → Security.
2. Select your Windows account.
3. Verify Read and Write are allowed.
4. If permitted by your organization, select Edit and grant those rights.

If the message instead says the file is in use, save and close the application holding it. OneDrive synchronizes it after the application releases the file ^6^.

Repair a confirmed sync-client problem

If the file is locally available, no checkout policy applies, and OneDrive still reports a synchronization error:

1. Close OneDrive from its taskbar menu.
2. Move the affected file temporarily outside the OneDrive folder.
3. Start OneDrive and wait until it reports Up to date.
4. Copy the file back into OneDrive.

Also check for unsupported characters and ensure the complete path is under 400 characters. If the problem affects many otherwise valid files, unlink/relink the work account or reset OneDrive as later repair options ^3^.

Immediate email workaround

In new Outlook, use Attach File → OneDrive or SharePoint, select the cloud file, and choose Send a copy if a traditional attachment is required. Alternatively, after downloading the file, use Attach File → Browse This Computer ^7^.

References

1. One Drive "Available when online" - Microsoft Q&A
2. Work with synced files in File Explorer | Microsoft Support
3. Fix SharePoint Online sync problems | Microsoft Support
4. What do the OneDrive icons mean? | Microsoft Support
5. SharePoint suddenly requiring admin access to save files for everyone in my organisation through file explorer, not online, when before it was working fine. - Microsoft Q&A
6. Troubleshoot OneDrive error: "This file can’t be synced" | Microsoft Support
7. [New Outlook](https://support.microsoft.com/outlook/mail/add-pictures-or-attach-files-to-emails-in-outlook)