Introduction

Microsoft has paused the rollout of the KB5002907 Microsoft 365 update after users reported that it deactivated — or in some cases completely removed — perpetual Office 2016 and Office 2019 installations.

KB5002907, titled "Optional update for out-of-date Microsoft 365 Apps installations," was released to help users update Microsoft 365 Apps installations that are more than 90 days out of date.

10 min
Time for 5 unrelated MSP customers to report issues
Sept 23
KB5002907 release date
2
Office versions affected (2016 and 2019)

This blog is based on reporting by Lawrence Abrams (September 26, 2026). Microsoft has confirmed it is investigating and has paused the rollout.

What Happened: Office Installs Deactivated or Removed

Shortly after the update was released, BleepingComputer was told by Christian Van Hautte, who runs an MSP in Belgium, that several of his customers suddenly found their perpetual Office installations showing as an "Unlicensed Product."

"Five unrelated customers contacted his company within approximately ten minutes on September 24, with dozens of PCs affected across the organizations."

— Christian Van Hautte, MSP owner in Belgium

"The affected installations are all Office 2016 and Office 2019 Home & Business (perpetual/one-time purchase licenses). The common factor is KB5002907, an update released around September 23 and described as targeting 'outdated Microsoft 365 Apps installations' — but it is clearly also landing on perpetual (non-subscription) Office installs and breaking their license state."

— Christian Van Hautte

Van Hautte said re-entering the original Office product key restored activation on affected systems.

Furthermore, Van Hautte warned that even though the update is listed as optional, it installed automatically on his customers' devices.

Who Is Affected

Product License Type Impact
Office 2016 Perpetual / one-time purchase Deactivated or removed
Office 2019 Perpetual / one-time purchase Deactivated or removed
Office 2016 / 2019 Home & Business Perpetual / one-time purchase Deactivated or removed

Reports from other administrators and users began appearing online at approximately the same time:

The update was labeled "optional" but installed automatically for many users. Perpetual Office licenses were the primary target — even though the update was described as targeting Microsoft 365 Apps installations.

The Mixed-Bitness Problem: Why Some Installs Disappeared

Van Hautte later discovered that KB5002907 appears to remove and reinstall, or migrate, the existing Office installation as part of its update process.

This is where things got worse for some businesses. Van Hautte says that on systems with Office components of different architectures — such as:

...the reinstall can fail because Microsoft Office setup does not allow mixing 32-bit and 64-bit Office products.

In those cases, the existing Office suite is removed but not successfully reinstalled, leaving the device without Office entirely.

Microsoft has not confirmed that mixed-bitness installations cause this behavior.

Microsoft's Response: Update Paused

After BleepingComputer contacted Microsoft about the reports, the company confirmed that it had paused the update while investigating the issue.

"We are aware of these reports and have paused the update while we investigate. Additional customer guidance will be communicated via appropriate channels."

— Microsoft spokesperson

Microsoft also updated the KB5002907 support bulletin to acknowledge the problems:

"Microsoft is investigating reports of unexpected results on some devices running Office 2016 or Office 2019 after this update is installed. To prevent additional devices from being affected, we have paused the rollout of this update."

— Microsoft KB5002907 support bulletin

Microsoft confirms that affected Office installations can suffer from two different problems:

Full Timeline of the Incident

September 23
KB5002907 Released

Microsoft releases "Optional update for out-of-date Microsoft 365 Apps installations" through Windows Update.

September 24
MSP Reports First Incidents

Christian Van Hautte's MSP in Belgium receives calls from 5 unrelated customers within 10 minutes, with dozens of PCs affected. Office installs showing as "Unlicensed Product."

September 24-25
Reports Spread Online

Reddit users, administrators, and Microsoft forum posters report similar issues — Office deactivated or completely uninstalled on systems with legitimate perpetual licenses.

September 26
Microsoft Pauses Update

After BleepingComputer contacts Microsoft, the company confirms it has paused the update while investigating. The KB5002907 support bulletin is updated to acknowledge the issue.

How to Recover: Reactivation and Reinstall

If your business has been affected, here's how to recover:

If Office Shows as "Unlicensed Product"

  1. Open any Office application (Word, Excel, etc.)
  2. Go to File → Account
  3. Select Activate Product or Change License
  4. Enter your original Office 2016 or 2019 product key
  5. Some users have reported needing to sign into a Microsoft account and select the license rather than just entering the key
  6. Restart Office and verify activation

If Office Was Completely Removed

  1. Locate your original Office 2016 or 2019 product key
  2. Download the Office installer from Microsoft's official setup portal or your licensed distribution source
  3. Run the installer and reinstall Office
  4. Enter your product key when prompted
  5. Verify activation and test the applications

If you don't have your original product key, check your Microsoft Account's purchase history, your email records, or contact Microsoft support.

Why This Matters for Every Business

This incident is a reminder of something every business should understand: "optional" updates are not always optional, and even well-intentioned updates can cause serious disruption.

If your business relies on Office 2016 or 2019 perpetual licenses, this incident shows exactly why patch management discipline and testing are essential — not optional.

Why Businesses Rely on Managed IT Services for Update Management

Here's the hard truth: most small and mid-sized businesses have no way to prevent this kind of update disaster on their own. Updates install automatically. Users don't know to defer them. And when something breaks, there's no one to catch it before dozens of PCs are affected.

That's where Managed IT Services (MSPs) come in. A modern MSP provides the patch management discipline, testing processes, and rapid response capability that protect a business from exactly this kind of incident.

What a Managed IT Services Partner Does for Update Management

When updates like KB5002907 break things, a good MSP partner has already prevented or minimized the impact. Here's what that looks like:

  • Controlled update deployment — Updates are tested in a pilot group before broad rollout
  • Update deferral policies — Updates are delayed by days or weeks to catch issues like this before they hit your organization
  • Automatic backup and recovery — If an update breaks something, you can roll back quickly
  • Proactive monitoring — Alerts on unusual update behavior, activation failures, or application errors
  • Rapid response — When incidents happen, your MSP can act immediately — often before you even know something broke
  • License management — Tracking product keys and activation records so recovery is straightforward
  • Mixed-architecture awareness — Knowing which endpoints have 32-bit vs 64-bit Office components and warning about known issues
  • Employee communication — Notifying users of issues and expected recovery timelines
  • Vendor engagement — Coordinating with Microsoft when vendor-side issues occur
  • Documentation — Recording what happened, what was affected, and what was done to fix it
Book a Free Patch Management Assessment

Why SMBs Choose Managed IT Over DIY

For most organizations, the "we'll deal with it if it happens" approach fails when updates break critical systems:

If your business relies on Office 2016 or 2019 perpetual licenses — and you don't have patch testing or rollback capability — a Managed IT Services partner can help you prevent this class of incident.

What to Ask a Potential MSP Partner About Update Management

If you're evaluating MSPs (or wondering whether your current one is doing enough), ask these questions:

At SystemLogicIT, we provide Managed IT Services and Microsoft 365 governance tailored to businesses across the United States and United Kingdom. If your organization needs help with patch management, update testing, or recovery from incidents like this, we'd be glad to talk.

What Businesses Should Do

Whether you manage IT in-house or through a partner, here's a practical checklist based on this incident:

If your organization needs help with patch management, update testing, or recovery from this incident, consider working with a Managed IT Services partner.

Final Thoughts

The KB5002907 incident is a reminder that updates are not always safe, and "optional" doesn't always mean optional. A well-intentioned Microsoft update designed to help out-of-date installations ended up disabling legitimate Office 2016 and 2019 licenses across multiple organizations.

Microsoft did the right thing by pausing the update quickly. But the incident exposed a gap that most small and mid-sized businesses have: no testing, no rollback, no monitoring, no rapid response.

The businesses that avoided this incident — or recovered from it quickly — were the ones with patch management discipline already in place.

Key takeaways:

If your organization needs help with patch management, update testing, or Office license recovery, contact SystemLogicIT for expert Managed IT Services and Microsoft 365 governance across the United States and United Kingdom.

SL
SystemLogicIT Team
Managed IT Services & Microsoft 365 Experts
Helping US and UK organizations manage patches, protect Office installations, and respond to update incidents.