Some users may intermittently receive no response when submitting queries in Microsoft 365 Copilot Chat

Title: Some users may intermittently receive no response when submitting queries in Microsoft 365 Copilot Chat User impact: Users may have intermittently received no response when submitting queries in Copilot Chat. More info: Affected users may have seen errors such as “Something went wrong” or “I couldn’t help with that” when they submitted queries. Final status: While we were in the process of analyzing the "499" error codes in the request flow, system monitoring indicated that the service had returned to normal health. We've confirmed that the issue is no longer occurring and we'll continue to monitor the service to ensure that the problem doesn't happen again. Scope of impact: Some users located in West Europe that attempted to submit queries to Copilot Chat were affected. Start time: Wednesday, November 11, 2026, at 9:00 AM UTC End time: Wednesday, November 11, 2026, at 5:43 PM UTC This is the final update for the event.

Title: Some users may intermittently receive no response when submitting queries in Microsoft 365 Copilot Chat User impact: Users may intermittently receive no response when submitting queries in Copilot Chat. More info: Affected users may see errors such as “Something went wrong” or “I couldn’t help with that” when submitting queries. Current status: We've identified an increase in "499" error codes coming from the portion of service infrastructure responsible for facilitating Copilot Chat query responses, which occur during the request flow that communicates queries to that infrastructure. Our initial review suggests that the affected infrastructure isn't handling the request traffic at optimal levels of efficiency. Another theory suggests that the request traffic may be routing incorrectly. While we continue to investigate the root cause, we're observing that the error rate is decreasing and the service is self-recovering. We'll continue to monitor our service health telemetry while we determine how to expedite the recovery. Scope of impact: Some users located in West Europe that are attempting to submit queries to Copilot Chat are affected. Start time: Wednesday, November 11, 2026, at 9:00 AM UTC Next update by: Wednesday, November 11, 2026, at 7:00 PM UTC

Title: Some users may encounter errors when submitting queries in Microsoft 365 Copilot Chat User impact: Users may encounter errors when submitting queries in Copilot Chat. More info: Affected users may see errors such as “Something went wrong” or “I couldn’t help with that” when submitting queries. Current status: We're reviewing service monitoring telemetry to isolate the root cause and determine our next troubleshooting steps. Scope of impact: Impact is specific to some users attempting to submit queries in Copilot Chat. Next update by: Wednesday, November 11, 2026, at 5:00 PM UTC