Urgent – Microsoft 365 Application Crashes Across Enterprise Environment

Question

Hello,

Victor LalouxI am an IT Support Engineer working in a large enterprise environment and we are currently experiencing a critical issue affecting a significant number of users.

Since the end of June 2026, users have been reporting random crashes and freezes across the Microsoft 365 suite, primarily affecting:

• Outlook
• Excel
• Word
• PowerPoint

The applications either display "has stopped working" messages or become "Not Responding", requiring users to terminate the process via Task Manager before they can continue working.

The issue is widespread and has a major impact on business operations and user productivity.

Troubleshooting already performed

The following actions have been carried out on affected devices without resolving the issue:

• Online Repair of Microsoft 365 Apps.
• Installation of all available Windows 11 updates.
• Removal and verification of Office add-ins (Excel, Outlook, etc.).
• Testing Office applications in Safe Mode.
• Uninstallation of potentially related Windows updates:
  • KB5095093
    • KB5092427
    • Multiple workstation reboots after updates.
    • Verification that Microsoft 365 Apps are fully updated.

Despite these efforts, the crashes and freezes continue to occur across numerous devices and users.

Additional Information

The symptoms appear very similar to recent reports from other customers regarding Microsoft 365 applications freezing or crashing following recent June 2026 updates. The behavior is observed across different hardware models and user profiles, making it difficult to identify a common local root cause.

Assistance Required

Could you please assist us with:

• Confirming whether there is a currently known Microsoft 365 or Windows issue matching these symptoms.
• Providing any recommended diagnostic logs or data collection procedures.
• Advising on available workarounds or fixes.
• Confirming whether any upcoming patches address this behavior.

Given the scale of the impact within our environment, we would greatly appreciate your assistance in resolving this issue as quickly as possible.

Thank you for your support.

Kind regards,

Victor Laloux

Answer 1

Hello @Laloux Victor

Thank you for your feedback. First, I would like to clarify that this is a user-to-user support forum. Moderators do not have access to your tenant environment, backend diagnostics, or escalation channels, so we cannot directly confirm whether a specific service incident is affecting your organization.

Regarding KB5095093, Microsoft has acknowledged a known issue where Microsoft Office applications may fail to open when launched from certain third-party applications. However, based on the troubleshooting you've already completed:

• Removal and verification of Office add-ins
• Testing Office applications in Safe Mode

the fact that the crashing/freezing behavior persists suggests there may be another factor involved. Could you help check the following on one of the affected devices?

• Microsoft 365 Apps version and build number
• Update channel (Current Channel, Monthly Enterprise Channel, Semi-Annual Enterprise Channel, etc.)

For comparison, there have been several Microsoft 365 Apps releases in late June 2026, including:

• Version 2606 (Build 20131.20112) - June 30, 2026
• Version 2606 (Build 20131.20090) - June 25, 2026

It would be useful to determine whether the issue is tied to a specific Office build. If the affected devices are not already running the latest build, you may also want to update a small test group and see whether the behavior changes. Conversely, if the issue started immediately after a recent update, consider rolling back a few affected devices to an earlier Office build to determine whether the problem is build-related.

Additionally, since the issue appears to have started around the same timeframe as recent Windows updates, you may also want to test on a small group of affected devices by temporarily reverting the most recent Windows update (where appropriate and in accordance with your organization's change-management policies) to determine whether the behavior is being triggered by an Office build, a Windows update, or the interaction between the two.

Given the scale of the impact across multiple users and devices, I would also strongly recommend opening a Microsoft support case if you have not already done so. Microsoft Support has access to backend diagnostics and can collect crash dumps, analyze telemetry, and determine whether this is related to a broader product issue or a regression in a recent build.

In the meantime, I'll continue to help as much as I can from the forum side. Please try the version/build checks and, if possible, a rollback test on a small group of affected devices, then let me know the results.

Hope this helps.

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Answer 2

As already mentioned by Gabriel-N, since you are a business customer, the local admin in your organization will have to raise a support ticket with Microsoft business support. See https://learn.microsoft.com/en-us/microsoft-365/admin/get-help-support?view=o365-worldwide .