OneDrive Admin Checklist: shared library sync loops after restart for slow networks

On Windows 10 and Windows 11, shared libraries in OneDrive can enter a sync loop after every restart when the network connection is slow. The symptom is clear: OneDrive starts syncing a shared library, gets stuck at a certain percentage, then restarts the sync from the beginning. This cycle repeats indefinitely, blocking other sync operations and consuming bandwidth. The root cause is a combination of the default sync timeout being too short for slow networks and the library’s metadata failing to download completely before OneDrive re-evaluates the sync state. This article walks through an admin checklist to identify the misconfigured settings and apply the correct fixes so shared libraries sync reliably even on slow connections.

Why Shared Libraries Enter Sync Loops After Restart on Slow Networks

When a Windows device restarts, OneDrive must reinitialize all sync relationships, including shared libraries. For each shared library, the client downloads a metadata file that lists all files and their sync states. On a slow network — defined here as any connection with an average throughput below 2 Mbps or high latency above 150 ms — this metadata download can take longer than the client’s internal timeout.

OneDrive’s sync engine uses a throttling mechanism called ThrottlingAuto. This mechanism dynamically reduces the sync speed based on perceived network congestion. On slow networks, the throttling algorithm often misinterprets low throughput as congestion and further restricts the download speed. The metadata download then fails to complete within the timeout window. OneDrive marks the library as out of sync, discards the partial metadata, and restarts the entire process. This creates the loop.

Another contributing factor is the SyncBackupFeatureState registry key, which controls Known Folder Move (KFM) behavior. When KFM is enabled and the network is slow, the client may try to sync both personal folders and shared libraries simultaneously, exceeding the available bandwidth and causing shared library syncs to fail repeatedly.

Admin Checklist to Stop Shared Library Sync Loops

Use the following steps in order. Each step addresses a specific cause of the loop. Apply the fix at the device level or deploy it via Group Policy or Intune for multiple users.

1. Disable automatic throttling via registry
   Open Registry Editor as administrator. Navigate to HKEY_CURRENT_USER\Software\Microsoft\OneDrive\Accounts\Business1. Create a new DWORD (32-bit) value named ThrottlingAuto and set its value to 0. This disables the automatic bandwidth throttling that misidentifies slow networks as congested. Restart OneDrive. Test by restarting the device and verifying that the shared library sync completes without restarting.
2. Set a minimum download throughput via Group Policy
   Open the Local Group Policy Editor. Navigate to Computer Configuration > Administrative Templates > OneDrive. Double-click Set the maximum download throughput. Set it to Enabled and enter a value between 512 and 1024 Kbps. This reserves bandwidth for OneDrive sync traffic, preventing other applications from starving the sync process. Apply the policy and run gpupdate /force from an elevated command prompt.
3. Disable Known Folder Move temporarily for shared libraries
   In OneDrive settings, go to Sync and backup > Manage backup. Turn off backup for Desktop, Documents, and Pictures. This stops KFM from competing with shared library syncs. After the shared library completes its initial sync, you can re-enable KFM. For persistent slow networks, keep KFM disabled during device startup.
4. Update OneDrive to build 22.245.1206.0001 or newer
   Download the latest OneDrive setup from the Microsoft 365 admin center or onedrive.com/download. Run the installer with the /allusers switch for enterprise deployments. This build includes a fix that increases the metadata download timeout and improves retry logic for shared libraries.
5. Clear the sync cache for the affected library
   If the loop persists, stop OneDrive. Navigate to %LOCALAPPDATA%\Microsoft\OneDrive\settings\Business1. Delete the folder with the name matching the shared library’s tenant ID and site ID. Restart OneDrive. This forces a fresh metadata download and clears any corrupted cache files that may be causing the loop.
6. Configure network QoS policy to prioritize OneDrive traffic
   Open the Local Group Policy Editor. Navigate to Computer Configuration > Windows Settings > Policy-based QoS. Create a new policy named OneDrive Sync. Specify the application path as %LOCALAPPDATA%\Microsoft\OneDrive\OneDrive.exe. Set DSCP value to 46 and throttle rate to 1 Mbps. This ensures that OneDrive traffic is prioritized over non-essential traffic on slow networks.

If Shared Library Sync Still Loops After the Main Fixes

OneDrive shows error 0x8004de40 after restart

Error 0x8004de40 indicates that the OneDrive credential token expired during the slow metadata download. The fix is to re-authenticate. Go to OneDrive settings > Account > Unlink this PC. Relink the account. This refreshes the token and forces a new metadata download.

Shared library sync completes but files show grey check marks

Grey check marks mean the files are available online only but the placeholder thumbnails failed to download. This is a symptom of the same slow network condition. Run the following command in an elevated command prompt: onedrive.exe /reset. Wait 60 seconds, then run onedrive.exe to restart the sync client. After the reset, the grey check marks should change to solid green.

Only one specific shared library loops while others sync fine

This points to a corrupted library metadata file rather than a network issue. Ask the library owner to create a new shared link with edit permissions and share it again. Remove the original library from OneDrive by right-clicking it and selecting Stop syncing. Then sync the library using the new link.

Files On-Demand vs Always Keep on This Device: Key Differences for Slow Networks

Item	Files On-Demand	Always Keep on This Device
Metadata download size	Small (file names and thumbnails only)	Large (full file content for all files)
Sync loop risk on slow networks	Lower — metadata completes faster	Higher — full downloads exceed timeout
Initial sync time after restart	Seconds to minutes	Hours for libraries with many files
Recommended for shared libraries on slow networks	Yes — use this setting exclusively	No — avoid for shared libraries below 2 Mbps
Admin control via Group Policy	Enable via Set the default location of the OneDrive folder policy	Not centrally configurable; user must right-click each library

After applying the checklist, your shared libraries should sync fully after each restart without entering a loop. Verify the fix by restarting the device and monitoring the OneDrive activity center for the library status. For ongoing management, consider deploying the Set the maximum download throughput Group Policy to all devices that connect from slow networks. As an advanced tip, use the Get-OneDriveSyncStatus PowerShell cmdlet from the Microsoft OneDrive sync admin module to audit sync completion times across your tenant.