Not being able to edit SharePoint files synced to OneDrive via desktop apps, must go to office online.

Grant users Contribute/Edit permission on the folder containing the files—not only on individual files—because OneDrive desktop sync cannot provide writable access when the synced parent container is read-only.^1^

Recommended permission design

1. Open the document library in SharePoint.
2. Select the folder that users need to edit.
3. Select Manage access.
4. Open Advanced permission settings if necessary.
5. Stop inheriting permissions for that folder.
6. Grant the relevant users or group Edit or at least Contribute on the folder.
7. Remove any conflicting direct permission entries that leave those users with read-only access.
8. Open Settings → Library settings → Permissions for this document library → Check Permissions, enter an affected user, and verify that the user has Contribute or higher for the synchronized location.

Microsoft documents that synced files remain read-only unless the user has Contribute permissions or higher. A read-only SharePoint library or folder is also a documented cause of OneDrive upload failures.^1^ ^2^

If users must edit only selected documents, move those documents into a dedicated folder or library and grant Edit/Contribute there. This preserves least-privilege access without relying on individual-file exceptions beneath a read-only synchronized folder.

Why browser editing still works

SharePoint can assign a higher permission directly to an individual file, so the browser can honor that file-specific Edit grant.^3^

The OneDrive/Office desktop path also has to synchronize changes through the containing folder or library. Microsoft states that a lock icon on synchronized files means they are synced read-only, potentially because the user lacks permission to edit or because the library has settings incompatible with writable synchronization.^4^

Therefore, the current arrangement—read/no access on the parent folder combined with Edit on selected files—can work in Office for the web but does not provide the permission scope needed for writable desktop synchronization. The available documentation does not establish why this began only recently, so it should not be attributed to a particular service change without confirmation from Microsoft support.

If folder permissions are already Contribute or higher

Have the site owner check these library settings:

• Settings → Library settings → Versioning settings
  • Require Check Out: No
  • Draft Item Security: Any user who can read items
  • Review whether content approval is required.
• Library settings → Columns
  • Check for required metadata columns.
• Library settings → Validation settings
  • Check for library validation rules.
• Library settings → Advanced settings
  • Offline Client Availability: Yes

Checkout requirements, validation or required metadata, and restrictive draft-item security cause SharePoint documents to synchronize as read-only.^1^ Do not remove governance controls solely to enable sync; confirm any change with the library owner because it affects all library users.

If none of those conditions applies, test the native library connection:

1. Remove the affected OneDrive shortcut using Remove shortcut from My files—do not delete the folder.
2. Open the SharePoint library in a browser.
3. Select Sync.
4. Open the resulting organization folder in File Explorer and test editing.

If the direct Sync connection works but the shortcut remains read-only, collect the OneDrive version, Office version, affected library URL, and screenshots of Check Permissions, then open a Microsoft 365 support request as a shortcut-specific sync issue.

References

1. Restrictions and limitations in OneDrive and SharePoint | Microsoft Support
2. Permissions needed to upload files in OneDrive for work or school | Microsoft Support
3. Document collaboration and co-authoring | Microsoft Support
4. Sync SharePoint and Teams files with your computer | Microsoft Support