OneDrive Coauthoring Fails When Users Open Files From Explorer

When multiple users in your organization try to edit the same Office file simultaneously from File Explorer, OneDrive coauthoring may fail silently. Instead of seeing real-time collaboration, users encounter a file lock message or are forced into read-only mode. This problem typically occurs because the Office application opens the file in a mode incompatible with coauthoring when launched directly from Explorer rather than from the OneDrive web app or the Office app’s recent files list. This article explains the root cause, provides step-by-step fixes to restore coauthoring, and covers related failure patterns you may encounter.

Why Coauthoring Fails When Opening Files From Explorer

The core issue lies in how Office applications handle file open requests from File Explorer versus from the OneDrive sync client. When you double-click a file in Explorer, the Windows shell passes the file’s local path to Office. Office then opens the file from the local OneDrive folder, which by default acquires an exclusive write lock on the file. This lock prevents other users from editing the same file simultaneously, effectively disabling coauthoring.

OneDrive’s sync client supports two file open modes:

Legacy Mode (Default for Explorer Opens)

In legacy mode, Office opens the local copy of the file and treats it as a standalone document. OneDrive syncs changes back to the cloud only after the file is saved and closed. While the file is open, other users see a lock icon and a message that the file is in use. Coauthoring does not work because Office never establishes a real-time collaboration session with the cloud version.

Coauthoring Mode (Used by Office Apps and Web)

When you open a file from the Office app’s Recent list, from OneDrive.com, or from the OneDrive sync status icon menu, Office opens the file in coauthoring mode. In this mode, Office communicates directly with the cloud copy, and multiple users can edit simultaneously. Changes appear in near real time, and file locks are not applied.

The default behavior for Explorer opens is controlled by the OneDrive setting Use Office applications to sync Office files that I open. When enabled, this setting forces Office to use the legacy sync path for any file opened from Explorer. Disabling this setting is the primary fix.

Steps to Enable Coauthoring for Files Opened From Explorer

1. Open OneDrive Settings
   Right-click the OneDrive cloud icon in the system tray near the clock. Select Settings from the context menu. If you do not see the icon, click the up arrow to show hidden icons.
2. Go to the Office Tab
   In the OneDrive Settings window, click the Office tab. This tab contains a single checkbox that controls how Office files open from Explorer.
3. Disable the Sync Setting
   Uncheck the box labeled Use Office applications to sync Office files that I open. A confirmation dialog may appear warning that this change affects how files open. Click OK to confirm.
4. Close and Reopen OneDrive Settings
   Click OK to close the Settings window. Open Settings again and verify the checkbox remains unchecked. If it re-enables itself, a Group Policy or administrative setting may be overriding the change.
5. Test Coauthoring
   Open an Office file from File Explorer by double-clicking it. The file should now open in coauthoring mode. Ask a colleague to open the same file simultaneously. Both of you should see each other’s cursor presence and be able to edit without lock messages.

Alternative Method: Register a Registry Key for Coauthoring

1. Open Registry Editor
   Press Windows + R, type regedit, and press Enter. Click Yes if prompted by User Account Control.
2. Navigate to the Office Common Key
   Go to HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Common\Internet. If the Internet key does not exist, right-click the Common folder, select New > Key, and name it Internet.
3. Create a DWORD Value
   Right-click in the right pane, select New > DWORD (32-bit) Value. Name it OpenDocumentsReadWriteWhileBrowsing.
4. Set the Value to 1
   Double-click the new value, set Value data to 1, and click OK. Close Registry Editor.
5. Restart Office Applications
   Close all open Office apps. Reopen a file from Explorer and test coauthoring.

If OneDrive Coauthoring Still Has Issues After the Main Fix

OneDrive Shows a Red X on Shared Office Files

A red X in the OneDrive sync status column indicates a sync conflict or error. This often happens when a file was opened in legacy mode before the setting was changed. The file may have a lock that persists. Right-click the file in Explorer and select OneDrive > View sync conflicts. Resolve any conflicts by keeping the version you want. Then ask all users to close the file and reopen it.

Coauthoring Works in Web App but Not in Desktop App

If coauthoring works on OneDrive.com but fails in the desktop Office app, the issue is likely the Office version. Coauthoring requires Office 2019, Office 2021, or Microsoft 365 Apps for enterprise. Office 2016 and earlier do not support real-time coauthoring. Check your Office version by opening any Office app, going to File > Account, and looking under Product Information.

Group Policy Overrides the OneDrive Setting

In managed environments, IT administrators may enforce the Use Office applications to sync Office files setting via Group Policy. If the checkbox in OneDrive settings re-enables after you uncheck it, contact your IT department. They can set the policy Computer Configuration > Administrative Templates > Microsoft OneDrive > Use Office 2016 to sync to Disabled.

Files Opened From Explorer vs Coauthoring Mode: Key Differences

Item	Legacy Mode (Explorer Default)	Coauthoring Mode (After Fix)
File lock behavior	Exclusive write lock applied	No lock; multiple users edit simultaneously
Change visibility	Changes visible only after save and sync	Changes appear in near real time
Sync trigger	File save or close	Continuous cloud communication
Office app required	Any Office version	Office 2019 or later, Microsoft 365
OneDrive setting control	Checkbox enabled	Checkbox disabled

After disabling the sync setting and applying the registry key if needed, your users can open files from File Explorer and enjoy full coauthoring. Test the change with a shared Excel workbook first. For advanced troubleshooting, use the OneDrive sync status icon to check for file conflicts and ensure all users are on the same Office channel.