Microsoft 365 Alert – Service Degradation – Power BI – Some users are experiencing issues where DirectLake semantic models built on top of warehouses are failing to refresh – RESOLVED

Announcements Shagufta Naaz

02/02/2026 09:05:00 AM

NHSmail Reference: INC46738956

Microsoft Reference: PB1225795

Issue Status: RESOLVED

Issue Description: Users are experiencing issues where DirectLake semantic models built on top of warehouses are failing to refresh.

Final Update: 05/02/2026 09:05:00 AM – Microsoft has confirmed that the deployment of our code change has completed, and they have tested internally to validate that the impact is remediated.

Scope of impact: Your organisation was affected by this event, and some users that were using DirectLake semantic models built on top of warehouses were impacted.

Root cause: An issue in a recent deployment to the STO implemented a header handling change that was causing the STO to send invalid HTTP headers to Direct Lake semantic models and resulted in the failing refreshes.

Next steps: Microsoft is further reviewing the recent deployment to understand what specific aspect of it caused the STO to send invalid HTTP headers to Direct Lake semantic models, and to understand what prevented it from being detected in their update testing and validation procedures, which will allow them to prevent similar issues in future deployments.