(Resolved) Users are unable to open PDFs within SharePoint Online

As of 10:30 AM on December 3, 2025, an issue is preventing the opening of PDF files in SharePoint.
However, PDF files can be viewed by downloading them.

The estimated time for resolution is currently under investigation.

[Update 13:15, December 3, 2025]
An announcement stated that the issue was restored at 13:00 on December 3, 2025.