Microsoft 365 Alert – Service Degradation – SharePoint Online – Some users may be unable to open PDFs within SharePoint Online – RESOLVED

Announcements Arpan Das

03/12/2025 09:18:00 AM

NHSmail Reference: INC46696685

Microsoft Reference: SP1191627

Issue Status: RESOLVED

Issue Description: Users may be unable to open PDFs within SharePoint Online

Current Update: 03/12/2025 09:18:00 AM – Microsoft have determined that an experimental feature change was rolled out more broadly than intended due to a configuration issue with a recent service update. They have disabled the problematic changes throughout the affected environment and verified that impact is resolved.

Scope of impact: Users who attempted to open PDFs within SharePoint Online may have been affected by this event.

Root cause: An experimental feature change was rolled out more broadly than intended due to a configuration issue with a recent service update.

Next Steps: Microsoft are reviewing their update testing and validation methods to better identify the potential for configuration issues such as this prior to deployment and prevent similar impact in the future.