OneDrive Admin Checklist: shared library sync loops after restart for Mac users

Mac users in your organization may see OneDrive enter a sync loop after restarting the computer. The OneDrive icon shows syncing, then stops, then starts again without completing. This problem typically happens with shared libraries that have deep folder structures or a large number of files. This article explains why shared libraries trigger sync loops on Mac, provides a step-by-step admin checklist to break the loop, and lists related failure patterns you should check before contacting support.

Why OneDrive Shared Libraries Enter Sync Loops After Restart on Mac

When a Mac restarts, OneDrive re-evaluates all synced libraries. For shared libraries, the local sync database can become stale if the library was modified while the user was offline or if a previous sync was interrupted. OneDrive then tries to reconcile the local state with the server state, but the database lacks a valid delta token. This forces a full re-scan of the library. On libraries with more than 10,000 items or nested folders, the re-scan can time out, causing OneDrive to restart the sync cycle from the beginning. The result is an infinite loop: scan, time out, restart, scan again.

Two specific behaviors on macOS 14 Sonoma and later make this worse. First, macOS aggressively suspends background processes after a restart to save battery. OneDrive may be suspended mid-sync, corrupting the local cache. Second, the Apple File System APFS performs snapshot-based backups that can lock files OneDrive is trying to write, causing the sync engine to fail and retry. These factors combine to create a persistent loop that only breaks when the local cache is cleared or the library is re-added.

Admin Checklist: 5 Steps to Stop a Shared Library Sync Loop

Follow this checklist in order. Each step is designed to isolate the problem without forcing the user to re-download the entire library.

1. Check OneDrive Sync Status
   Open OneDrive from the menu bar. Click the OneDrive icon and select Help & Settings > Preferences > Account. Under Shared Libraries, look for the library that shows a spinning icon or a status that changes every few seconds. Note the library name and the number of items shown. If the number jumps up and down, the loop is active.
2. Pause and Resume OneDrive Sync
   In the same Preferences window, click the Network tab. Set Download rate limit to 1 Mbps temporarily. Click Pause sync for 2 hours, wait 30 seconds, then click Resume sync. This forces OneDrive to request a fresh delta token from the server instead of continuing the corrupted local scan. If the loop stops, the issue was a stale local token. Revert the rate limit to its original value.
3. Uncheck and Re-Check the Shared Library
   Go to Preferences > Account > Shared Libraries. Uncheck the box next to the looping library. Wait 10 seconds. Re-check the box. OneDrive will re-authenticate the library and download a new sync token. This is the most effective fix and resolves about 80 percent of sync loops. If the loop returns after the next restart, proceed to step 4.
4. Delete the Shared Library Local Cache
   Quit OneDrive completely. Open Finder and press Shift+Command+G. Enter ~/Library/Application Support/OneDrive/settings/Business1/SharedWithMe. Locate the folder with the same name as the looping library. Inside it, delete the files ending in .db and .db-wal. Do not delete the folder itself. Restart OneDrive. The library will re-sync from scratch, but only the metadata cache is rebuilt, not the file content. This typically takes 5 to 10 minutes for a library with 50,000 items.
5. Remove and Re-Add the Shared Library
   If the loop persists, remove the library entirely. In Preferences > Account > Shared Libraries, click the three dots next to the library and choose Remove from OneDrive. Confirm the removal. Restart OneDrive. Re-add the library by clicking Add a shared library and selecting it from the list. This is the nuclear option and forces a full re-sync of all files. Warn the user that re-syncing a large library may take several hours.

If OneDrive Still Loops After the Main Fix

If the above checklist does not stop the loop, check these three related failure patterns.

OneDrive Syncs Forever After macOS Update

A macOS update can change how OneDrive interacts with APFS snapshots. After a major update like 14.1 to 14.2, OneDrive may fail to write its delta token file. The fix is to run OneDrive > Help & Settings > Preferences > Advanced > Reset OneDrive. This clears the entire local cache and forces a fresh download of all libraries. It takes longer but guarantees a clean state.

OneDrive Shows a Red X on Shared Office Files

A sync loop can leave some files with a red X icon even after the loop stops. This happens because the file status cache is corrupted. Open the file from the web browser, make a small edit, save it, and then open it from the local folder. OneDrive will re-sync the file and clear the red X. For multiple files, use the OneDrive > Help & Settings > Pause sync > Resume sync trick to trigger a bulk status refresh.

OneDrive Cannot Find the Shared Library After Restart

If the shared library disappears from the Finder sidebar after a restart, the library may have been removed from the user’s OneDrive account by an admin. Check the Microsoft 365 admin center under Admin centers > SharePoint > Active sites. Verify that the site collection for the shared library is not deleted or in read-only mode. If the site is active, ask the user to go to Preferences > Account > Shared Libraries and click Add a shared library to re-discover it.

Shared Library Sync Behavior: Mac vs Windows

Item	macOS OneDrive	Windows OneDrive
Delta token storage	~/Library/Application Support/OneDrive/settings/Business1/SharedWithMe	%LocalAppData%\Microsoft\OneDrive\settings\Business1\SharedWithMe
Background process priority	Low – macOS suspends after restart	Normal – Windows keeps sync active
Typical sync loop cause	Stale delta token + APFS lock	Corrupted local database file
Fix without re-download	Uncheck/recheck library	Reset OneDrive from Settings

The table shows that Mac users are more likely to hit sync loops due to OS-level suspension and file system locking. The uncheck/recheck method works on both platforms but is more reliable on Mac because it forces a new delta token without touching the local file cache.

After applying the checklist, the user should see a steady sync progress bar that completes within 30 minutes for most shared libraries. To prevent recurrence, instruct users to keep OneDrive running at login by checking Preferences > General > Start OneDrive automatically when I sign in to Windows on Mac this setting is named Open OneDrive automatically when I log into my Mac. Also set Preferences > Network > Download rate limit to at least 10 Mbps to avoid timeouts during the initial sync after restart.