Microsoft 365 Alert – Service Degradation – Microsoft 365 suite – Some users may be unable to access or open Excel files in multiple Microsoft 365 services – RESOLVED

07/02/2025 09:00:00 AM

NHSmail Reference: INC46469837

Microsoft Reference: MO1024882

Issue Status: RESOLVED

Issue Description: Some users may be unable to access or open Excel files in multiple Microsoft 365 services.

More info: Desktop applications were unaffected, and impacted Microsoft 365 services included but weren’t limited to:

– SharePoint Online
– OneDrive for Business
– Microsoft Teams

Current Update: 07/03/2025 09:00:00 AM – After reviewing failures within the portions of storage infrastructure responsible for facilitating access to Excel files in Microsoft 365 services, Microsoft isolated a regularly scheduled service update which contained a code change that caused impact. They rerouted request traffic to a different portion of infrastructure that doesn’t contain the offending code change and confirmed through service health monitoring that the impact is remediated.

Scope of impact: Impact was specific to some users who were served through the affected infrastructure that attempted to access or open Excel files.

Root Cause: A regularly scheduled service update contained a code change that caused impact.

Next steps: Microsoft are reverting the service update with the offending code change to have it analyzed and corrected, so that they can ensure that similar impact doesn’t occur in their next scheduled service update.