Microsoft 365 Alert – Service Degradation – Microsoft 365 suite – Users may have been unable to access Microsoft 365 web-based services correctly when using Google Chrome – RESOLVED

Announcements Shagufta Naaz

16/04/2026 9:20:00 AM

NHSmail Reference: INC46801412

Microsoft Reference: MO1281730

Issue Status: RESOLVED

Issue Description: Users may have been unable to access Microsoft 365 web-based services correctly when using Google Chrome.

More info: Impacted users may have experienced Microsoft 365 web apps and portals not rendering as expected when accessed via the Google Chrome browsers. This may have included, but was not limited to:
– Microsoft 365 admin center failing to load or missing UI elements such as search bars or pages
– An inability to open Excel or PowerPoint files through Microsoft 365 web pages
– Issues accessing apps such as OneDrive and Planner through the browser

This issue only impacted the latest version of Google Chrome (Version 147).
Other browsers, including Microsoft Edge, were unaffected. As a workaround, impacted users could have used the Microsoft Edge browser.

Additionally, desktop based clients were unaffected, and users may have been able to leverage these services.

Final Update: 17/04/2026 9:20:00 AM– Microsoft has completed the mitigation actions, and telemetry showed that the issue is resolved. Users may need to refresh their browser pages to experience relief.

Scope of impact: Some users attempting to access Microsoft 365 web-based services via Google Chrome (version 147) may have been impacted.

Preliminary root cause: As part of broad changers related to DigiCert Global Root CA (G1), Google Chrome no longer trusts these authentication configurations (more information can be found https://knowledge.digicert.com/alerts/digicert-root-strategy-aligning-with-industry-standards). In preparation, most Microsoft 365 web-based services had transitions to an alternate authentication configuration authorities, however, a small number were not fully addressed. Once the Google Chrome change occurred, the authentication configurations were no longer accepted, resulting in impact.

Next steps: Microsoft are investigating why some services had not fully transitioned off the specific authentication configurations. They will provide a preliminary Post-Incident Report within two business days and a final Post-Incident Report within five business days.