Microsoft 365 Alert – Service Degradation – SharePoint Online – Users may be unable to access Excel files through browser from SharePoint Online – RESOLVED

Announcements Arpan Das

11/06/2026 09:45:00 AM

NHSmail Reference: INC46848758

Microsoft Reference: SP1386381

Issue Status: RESOLVED

Issue Description: Users may be unable to access Excel files through browser from SharePoint Online.

More info: As a workaround, users can open the file in the Excel desktop app instead.

Final Update: 19/06/2026 09:26:00 AM – Following Microsoft’s completed fix deployment, their testing with affected users has validated that Excel files are able to be accessed through the browser, and that the impact has been remediated.

Scope of impact: Users accessing subsites with unique permissions not inherited from the parent site on SharePoint Online aren’t able to access files in Excel for the web browser.

Root cause: A code issue during the request flow for opening Excel files in SharePoint Online is causing errors.

Next update by: Thursday, June 18, 2026, at 9:30 PM UTC