MS365 (SharePoint) under investigation

Microsoft engineers have stated that deployment is taking longer than initially expected, and that they are isolating ways to expedite the remainder of their deployment to remediate impact as swiftly as possible.

Engineers have completed the validation of the fix and have initiated the release. A remediation timeline is expected to be released later this afternoon.

Code has been identified that is causing errors when opening Excel files. Engineers are developing a fix for the issue and anticipate that it will take time to complete. Once the fix is ready, they will begin deploying to the affected environment to remediate the impact.

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.

Latest Update from Microsoft:

We've determined that the recent update isn't the cause of impact. We're analyzing other recent updates along with testing additional service-side reproductions of this issue to isolate the root cause.

Users can't access Excel files through browser from SharePoint Online.