How to fix OneDrive 'File in Use' or 'Upload Blocked' sync errors

Summary

This guide helps you troubleshoot and resolve: How to fix OneDrive 'File in Use' or 'Upload Blocked' sync errors. Follow the steps below to fix the issue.

Common Causes

OneDrive sync errors such as 'File in Use' or 'Upload Blocked' typically occur when a file is locked by another application, a background process is preventing access, or there is a conflict between the local version and the cloud version. This guide will help you identify the cause and restore your synchronisation.

Quick Fix Steps

Before attempting more complex solutions, try these rapid fixes which resolve the majority of locking issues:

• Close all open applications: Ensure the file in question is not open in any program (Word, Excel, Adobe Acrobat, etc.).
• Restart OneDrive: Right-click the OneDrive icon (blue or white cloud) in the system tray, select Pause syncing, wait a few seconds, and then select Resume syncing.
• Restart your computer: This clears temporary file locks and terminates any hidden background processes that may be holding the file open.

Detailed Instructions

Method 1: Identify and Close Locking Processes

If you have closed the application but the error persists, a "ghost" process may still be running in the background.

1. Press Ctrl + Shift + Esc to open the Task Manager.
2. Click on the Processes tab.
3. Look for any instances of the application that was using the file (e.g., Microsoft Word or Excel).
4. Right-click the process and select End task.
5. Check the OneDrive icon to see if the sync error has cleared.

Method 2: Resolve File Name and Path Conflicts

OneDrive can block uploads if the file name contains unsupported characters or the file path is too long for Windows to process.

• Check for invalid characters: Ensure the file name does not contain " * : < > ? / \.
• Shorten the file path: If the file is buried deep within many folders, move it to a higher-level folder to reduce the character count of the full path.

Method 3: Reset OneDrive

If files are consistently blocked despite being closed, resetting the OneDrive application can refresh the sync engine without deleting your data.

1. Press the Windows Key + R to open the Run dialogue.
2. Copy and paste the following command and press Enter: %localappdata%\Microsoft\OneDrive\onedrive.exe /reset
3. If you see a "Windows cannot find..." message, try: C:\Program Files\Microsoft OneDrive\onedrive.exe /reset
4. Wait a few minutes, then manually start OneDrive from the Start menu if it doesn't restart automatically.

Troubleshooting Persistent Issues

Dealing with 'Office Upload Blocked'

When using Microsoft 365 apps, the "Office Upload Center" can sometimes clash with OneDrive's built-in sync.

1. Right-click the OneDrive cloud icon and select Settings.
2. Navigate to the Office tab (or Sync and backup > Advanced settings in newer versions).
3. Uncheck the box for Use Office applications to sync Office files that I open.
4. Click OK and restart your computer.

Checking for Permission Issues

If you cannot rename or move the file to resolve the block, you may have lost "Write" permissions for that specific folder.

1. Right-click the folder containing the blocked file and select Properties.
2. Go to the Security tab.
3. Ensure your user account has Full control or Modify permissions checked.

If you are experiencing broader Microsoft 365 connectivity issues, you may find our other guides useful, such as Troubleshooting Outlook Send/Receive Errors or Backing Up and Restoring Outlook Data Files.

If these steps do not resolve the issue, please Open a Ticket and provide a screenshot of the exact error message.

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