Microsoft is working to mitigate an ongoing incident that has been blocking users in Europe from accessing the company's AI-powered Copilot digital assistant.

Additionally, some users who can access the affected service may experience degraded functionality with specific features.

"We're investigating an issue in which users in the United Kingdom may be unable to access Microsoft Copilot, or experience degraded functionality with some features," Microsoft said when it acknowledged the issue one hour ago.

After reviewing service monitoring telemetry to isolate the root cause of the outage, Microsoft added that the incident was caused by a capacity scaling issue that is now being addressed.

"Indications from service monitoring telemetry suggest an unexpected increase in traffic has resulted in impact. We're continuing to investigate further to determine the next steps required," Microsoft said.

"We've identified an issue impacting service autoscaling to meet demand. We're manually scaling capacity to improve service availability, and we're monitoring this closely to ensure the expected outcome is achieved."

According to a service alert (CP1193544) seen by BleepingComputer, the outage may impact any user attempting to access Microsoft Copilot within the United Kingdom or Europe.

Microsoft is also tracking a separate incident (DZ1193516) causing some admins to experience errors when accessing Microsoft Defender for Endpoint features, including device inventory and threat analytics. While it has yet to share how many users are affected, the issue has been tagged as an incident in the admin center, a flag usually designating service problems with significant user impact.

One week ago, Microsoft also mitigated an outage that blocked access to some Defender XDR portal capabilities, including threat hunting alerts.

Update December 09, 07:54 EST: Microsoft has identified a separate issue behind the Copilot incident that is causing load-balancing problems and further adding to the overall impact.

"We’ve identified a separate issue affecting load balancing, which is also contributing to the overall impact. We’re making changes to our load balancing rules to provide relief. In parallel, we're continuing to work on increasing capacity to meet demand," Microsoft said.