Microsoft says some users are experiencing issues searching in Microsoft 365 apps, including Outlook on the web, Outlook desktop, SharePoint Online, and OneDrive.
According to an incident report seen by BleepingComputer and tracked under MO1456424 in the Microsoft 365 Admin Center, the root cause is what Microsoft describes as a recent deployment that causes resource utilization problems.
"Impact is specific to some users served through the affected infrastructure who are attempting to search for content in SharePoint Online, OneDrive, Outlook on the web, or Outlook desktop," Microsoft said.
"Our investigation identified that a recent deployment introduced a resource utilization inefficiency issue, leading to impact."
Microsoft says it has already developed a fix and deployed it to reduce resource pressure and restore service for all affected Microsoft 365 users.
While the company has yet to share which regions were impacted by this outage, it tagged it as an incident, which usually describes a critical service issue with noticeable user impact.
Last year, Microsoft mitigated similar incidents that broke file search for OneDrive, Outlook on the web, and SharePoint Online users.
In July, it also addressed a massive outage that took down Azure and Microsoft 365 services for users in North America after a bug in its automated network maintenance request system removed IP routes from more devices than intended.
On Monday, Microsoft resolved another incident that brought down GitHub, its website, the API, and many other services for more than eight hours, with users reporting server errors when trying to access GitHub, while others encountered problems loading commits, repositories, and Pull Request pages.
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