SharePoint Sync Not Working

When SharePoint library synchronization stops working, changes made to shared team sites fail to sync down to your local computer, and your local edits do not upload to the cloud. Because SharePoint synchronization is handled by the Microsoft OneDrive Sync Client background service, failures can stem from local client cache lockups, authentication conflicts, or library configuration limits.

This technical guide walks you through fixing sync hangs and resetting the OneDrive client sync directories on both Windows and macOS.

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1. Primary Causes of SharePoint Sync Failures

Before diving into operating system settings, understand the structural causes behind sync stalls:

• Office Cache Corruption: The Microsoft Office Document Cache (used for co-authoring) becomes desynchronized from the OneDrive sync engine.
• View Threshold Limits: The synced document library contains more than 300,000 files. Exceeding this limit causes extreme sync performance degradation and random freezes.
• Invalid File Name / Path Restrictions: File or folder names containing forbidden characters (such as ", *, :, <, >, ?, /, \, |) or exceeding the 260-character path limit.
• Stale Authentication Tokens: Cached Office 365 login credentials block secure handshakes.

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2. Initial Checks & Library Verification

Verify if the sync error is local or administrative:

1. Check Sync Status Online: Open the SharePoint document library in your web browser. Upload a test file. If this succeeds, the SharePoint server is responsive, and your local computer’s sync client is at fault.
2. Verify Library File Count: In SharePoint Online, check the total number of files in the library. If the count exceeds 300,000 items across all synced folders, OneDrive will struggle to synchronize. Consider un-syncing some subfolders using Choose Folders settings.
3. Check for “Required” Metadata: If a SharePoint column is set to “Required” or uses validation settings, files uploaded locally will remain checked out and cannot sync until the missing metadata properties are filled.

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3. Repair & Reset SharePoint Sync on Windows

On Windows, the OneDrive/SharePoint sync client uses standard OS folders and the Office file caching database.

A. Force Quit Sync Engines and Office Processes

1. Right-click the Taskbar and select Task Manager.
2. Select and end the following processes if they are running:
   • OneDrive.exe (OneDrive Sync Client)
   • Groove.exe (Legacy SharePoint Sync Client)
   • OfficeClickToRun.exe
3. Alternatively, run this command in Command Prompt (Admin):

   taskkill /f /im OneDrive.exe /im Groove.exe /im MSOSYNC.exe

B. Reset the OneDrive Sync Engine

Resetting OneDrive rebuilds the local SQL sync cache without deleting your files.

1. Press Windows Key + R to open the Run dialog box.
2. Type or paste the following path and press Enter:

   %localappdata%\Microsoft\OneDrive\onedrive.exe /reset

   (Note: If Windows reports “cannot find file”, try %programfiles%\Microsoft OneDrive\onedrive.exe /reset or %programfiles(x86)%\Microsoft OneDrive\onedrive.exe /reset instead).
3. Wait 2 minutes. The OneDrive system tray icon should reappear. If it does not, launch it manually via the Start Menu.

C. Clear the Office File Cache

Sometimes, Microsoft Office blocks files from syncing due to cache locks.

1. Force close all Microsoft Office applications (Word, Excel, PowerPoint).
2. Open the Run window (Win + R), type the path below, and press Enter:

   %localappdata%\Microsoft\Office\16.0\OfficeFileCache

3. Select all files inside this folder and delete them.
4. Relaunch OneDrive and open your Office files. The cache will rebuild cleanly.

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4. Repair & Reset SharePoint Sync on macOS

On macOS, SharePoint libraries sync through the OneDrive Mac application, integrated with Apple’s FileProvider system extension.

A. Reset the OneDrive Client App

1. Click the OneDrive icon in the macOS menu bar and select Quit OneDrive.
2. Open Finder and navigate to Applications.
3. Right-click the OneDrive app icon and select Show Package Contents.
4. Navigate to Contents → Resources.
5. Double-click the script file named ResetOneDriveApp.command (or ResetOneDriveAppStandalone.command depending on your installation).
6. A Terminal window will open automatically and run the reset script. Once completed, relaunch OneDrive, sign back in, and choose your SharePoint folder directories.

B. Purge Cached Credentials from macOS Keychain

If your SharePoint login session keeps prompting or gets stuck in a credentials loop:

1. Open Keychain Access via Spotlight.
2. Search for OneDrive and Microsoft Office.
3. Right-click and delete the following entries if present:
   • OneDrive Cached Credential
   • Microsoft Office Identities Cache
4. Restart your Mac and relaunch OneDrive to trigger a clean OAuth log-in.

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5. Summary Diagnostics Checklist

Target Issue	Actionable Resolution Command / Path	Expected Outcome
Windows Client Reset	%localappdata%\Microsoft\OneDrive\onedrive.exe /reset	Re-indexes all synced SharePoint libraries.
macOS Client Reset	Run ResetOneDriveApp.command from Package Resources	Restores default OneDrive application settings.
Clear Office Cache	Delete files in %localappdata%\Microsoft\Office\16.0\OfficeFileCache	Fixes co-authoring file lock and upload freezes.
Resolve Authentication	Purge OneDrive Cached Credential from Keychain/Credential Manager	Forces fresh credential sync with Office 365 tenant.