Activation Problems

How to Fix Microsoft 365 License Reactivation Error After Norton Update

Maira Mehtab Sep 20, 2026 869 views

Question details

The user is unable to reactivate Microsoft 365 after a Norton 360 update and package downgrade, despite trying various troubleshooting methods like reinstalling Office and using SaRA.

Product: Microsoft 365
Device & OS: not provided
Scenario: Attempting to restore Office application access and reactivate the Microsoft 365 license following a third-party antivirus software update.
Observed behavior: Office applications continuously prompt for license reactivation. Signing in with Microsoft credentials has no effect, and Error 29 may eventually appear during the process.

Before you start

Verify that your Microsoft 365 subscription is currently active on your Microsoft account dashboard, and ensure you have administrative privileges on your device to make software changes.

Solution 1Recommended

Completely Remove Norton 360 and Repair Office

Eliminate potential background security conflicts by using the official Norton removal tool, followed by an online repair of Microsoft Office.

Standard uninstallations often leave behind residual files and registry keys that can continue to interfere with Microsoft Office's licensing services.

Run the Norton Removal Tool

Download and run the official Norton Remove and Reinstall tool from the Symantec website to completely wipe Norton 360 from your system, then restart your PC.

Initiate Office Repair

Open the Windows Control Panel, navigate to 'Programs and Features', select your Microsoft 365 installation, and click 'Change'.

Perform an Online Repair

Choose the 'Online Repair' option and follow the on-screen prompts to thoroughly fix and restore the Office licensing components.

Attempt Reactivation

Open Microsoft Word or Outlook and try signing in with your Microsoft account credentials to reactivate the software before reinstalling any antivirus programs.

Isolate the Conflict: By attempting reactivation while Norton is completely removed, you can definitively determine if the security software was blocking the Microsoft authentication servers.

Solution 2

Diagnose Error 29 and Account Sync Issues

If Error 29 appears during the activation loop, investigate conflicting product keys or device synchronization states on your Microsoft account.

Free Microsoft Office alternative

Bypass Activation Errors with WPS Office

If Microsoft 365 license errors and security software conflicts are preventing you from accessing your work, switch to WPS Office. It provides a lightweight, highly compatible, and free alternative that does not rely on complex background activation services.

1. Download WPS Office: Navigate to the official WPS Office website and download the free installation package.
2. Install the Software: Run the downloaded installer and follow the simple setup wizard to complete the installation.
3. Open Your Documents: Launch WPS Office and instantly open your existing Microsoft Office files without any license reactivation prompts.

Avoid Microsoft 365 Error 29 and continuous reactivation loops entirely.Fully compatible with all major Microsoft Office formats including Word, Excel, and PowerPoint.Lightweight installation that doesn't conflict with Norton or other security software.Free to use with a clean, familiar interface for an effortless transition.

microsoft office alternative - wps office

Frequently Asked Questions

Why is Office asking for reactivation after a Norton update?

Security software updates can sometimes inadvertently block the background services Microsoft Office relies on to communicate with its licensing servers, causing the software to assume the license has expired or become invalid.

What does Error 29 mean during Microsoft 365 activation?

Error 29 typically indicates a backend licensing conflict. It often occurs when legacy product keys (like an old Office 2016 key) remain in the system registry or when security software interrupts the activation token exchange.

Why didn't the Microsoft Support and Recovery Assistant (SaRA) fix my activation issue?

While SaRA is effective at clearing cached credentials and resetting Office states, it cannot bypass active network blocks or registry locks enforced by third-party antivirus software like Norton. The security software must often be removed first.

Installation & Activation