OneDrive for Business shared library sync troubleshooting for slow networks: stays pending

When you add a shared library in OneDrive for Business, the sync status can remain stuck on “Pending” for hours, especially on slow or high-latency networks. This symptom means OneDrive is unable to complete the initial metadata download or file enumeration from the SharePoint or Teams site. The root cause is often a combination of network throttling, large library size, and OneDrive’s timeout behavior for metadata requests. This article explains why shared libraries get stuck in a pending state on slow connections and provides a set of fixes to get them syncing again.

Why a Shared Library Stays Pending on a Slow Network

When you add a shared library from SharePoint or Teams to OneDrive, the sync app must first download the library’s metadata — a list of all files, folders, permissions, and version history. On a slow network, this metadata download can exceed OneDrive’s internal timeout, causing the status to show “Pending” indefinitely. The sync engine uses a sequential request pattern: it sends a request for metadata, waits for a response, and if the response is delayed or dropped, the entire sync process stalls.

Several factors worsen this behavior:

Library Size and Depth

Libraries with thousands of files, deep folder hierarchies, or many nested subfolders generate massive metadata payloads. On a slow connection, downloading this payload can take minutes, and OneDrive may interpret the delay as a failure.

Network Latency and Packet Loss

High latency — above 150 ms round-trip time — increases the time for each metadata request-response cycle. Packet loss causes retransmissions, further extending the total time. OneDrive’s sync service has a default timeout of about 60 seconds per request. If the metadata download does not complete within that window, the request is retried, and the status remains pending.

Files On-Demand Interaction

Files On-Demand requires the sync app to maintain a constant connection to the cloud to fetch placeholder metadata. On a slow network, this connection can drop, causing the pending status to persist until the connection is reestablished.

Steps to Resolve Pending Sync for Shared Libraries on Slow Networks

Use the following methods in order. Start with the least invasive fix and escalate only if the problem persists.

1. Pause and resume sync
   Right-click the OneDrive icon in the system tray. Select Pause syncing and choose a duration such as 2 hours. After the pause ends, OneDrive automatically resumes. This forces the sync engine to reinitialize the metadata request from scratch. If the pending status clears, the original request had timed out and a fresh request succeeded on a less congested link.
2. Set a download rate limit
   Right-click the OneDrive icon and select Settings. Go to the Network tab. Under Download rate limit, check Limit download rate and set a value between 500 KB/s and 2 MB/s. Click OK. Throttling the download speed prevents OneDrive from sending bursts of requests that can trigger timeouts on slow links. After changing this setting, restart OneDrive from the system tray menu.
3. Remove and re-add the shared library
   Right-click the OneDrive icon and select Settings. Go to Sync and backup > Manage backup. Under Shared libraries, click Stop sync next to the stuck library. Wait 30 seconds. Then click Add a shared library, select the same library, and click Add. This clears corrupted local metadata and forces a clean download. On a slow network, this step often resolves the pending status.
4. Disable Files On-Demand for the library
   Open File Explorer. Navigate to the shared library folder. Right-click the folder and select Always keep on this device. This forces OneDrive to download all files locally. While this uses more disk space, it removes the dependency on constant metadata requests. Wait for the download to complete. The pending status should change to a green checkmark once all files are synced.
5. Increase the sync throttle timeout via Registry
   Press Win + R, type regedit, and press Enter. Navigate to HKEY_CURRENT_USER\Software\Microsoft\OneDrive. Right-click in the right pane, select New > DWORD (32-bit) Value, and name it ThrottleTimeoutMs. Set the value to 120000 decimal (120 seconds). Click OK. Restart OneDrive. This increases the metadata request timeout from 60 seconds to 120 seconds, giving slow networks more time to respond. Use this only if the previous steps fail.

If OneDrive Still Shows Pending After the Main Fix

OneDrive shows pending on only one shared library but others sync fine

The problematic library likely has a very large number of files or deep folder structure. Open the library in a browser and check the item count in the library settings page. If the library exceeds 30,000 items, split it into smaller libraries using SharePoint content management tools. Then remove and re-add each smaller library to OneDrive.

OneDrive sync engine crashes or freezes during metadata download

Corrupted cached files can cause the sync engine to crash. Exit OneDrive completely by right-clicking the system tray icon and selecting Quit OneDrive. Open File Explorer and navigate to %localappdata%\Microsoft\OneDrive. Delete the settings folder. Restart OneDrive and sign in again. This resets all cached metadata and forces a full re-sync.

Network proxy or firewall blocks metadata requests

Corporate proxies or firewalls sometimes block the specific URLs OneDrive uses for shared library metadata. Verify that the following URLs are allowed: onedrive.live.com and all subdomains, sharepoint.com and all subdomains, and files.1drv.com and all subdomains. Contact your network administrator to confirm these are not filtered. After unblocking, restart OneDrive.

Files On-Demand vs Always Keep on This Device: Key Differences for Shared Libraries

Item	Files On-Demand	Always Keep on This Device
Description	Placeholders only; files download on demand	All files downloaded and stored locally
Network dependency	Requires constant connection for metadata	Requires initial download only
Disk space usage	Minimal	Full file size
Best for slow networks	Not recommended — pending status common	Recommended — avoids metadata timeouts
Sync speed after initial download	Slower for each file access	Faster for local file access

On a slow network, Always keep on this device is the more reliable choice for shared libraries. It eliminates the metadata request overhead that causes the pending status. Switch back to Files On-Demand only after the network connection improves.

You can now resolve a shared library stuck on pending by throttling download speed, removing and re-adding the library, or disabling Files On-Demand. Start with the download rate limit setting in OneDrive preferences — it requires no file deletion and preserves your sync state. If the problem recurs, consider splitting large libraries into smaller units. As an advanced tip, use the Registry-based ThrottleTimeoutMs value to give slow connections up to 120 seconds per metadata request, which often resolves persistent pending status without removing the library.