Incident with Copilot agent sessionsOn February 27, 2026, between 22:53 UTC and 23:46 UTC, the Copilot coding agent service experienced elevated errors and degraded functionality for agent sessions. Approximately 87% of attempts to start or interact with agent sessions encountered errors during this period.
This was due to an expired authentication credential for an internal service component, which prevented Copilot agent session operations from completing successfully.
We mitigated the incident by rotating the expired credential and deploying the updated configuration to production. Services began recovering within minutes of the fix being deployed.
We are working to improve automated credential rotation coverage across all Copilot service components, add proactive alerting for credentials approaching expiration, and validate configuration consistency to reduce our time to detection and mitigation of issues like this one in the future.
Feb 27, 23:18 - 23:49 UTC
Code view fails to load when content contains some non-ASCII charactersStarting February 26, 2026 at 22:10 UTC through February 27, 05:50 UTC, the repository browsing UI was degraded and users were unable to load pages for files and directories with non-ASCII characters (including Japanese, Chinese, and other non-Latin scripts). On average, the error rate was 0.014% and peaked at 0.06% of requests to the service. Affected users saw 404 errors when navigating to repository directories and files with non-ASCII names. This was due to a code change that altered how file and directory names were processed, which caused incorrectly formatted data to be stored in an application cache.
We mitigated the incident by deploying a fix that invalidated the affected cache entries and progressively rolling it out across all production environments.
We are working to improve our pre-production testing to cover non-ASCII character handling, establish better cache invalidation mechanisms, and enhance our monitoring to detect this type of failure mode earlier, to reduce our time to detection and mitigation of issues like this one in the future.
Feb 27, 03:08 - 06:04 UTC
High latency on webhook API requestsBetween February 26, 2026 UTC and February 27, 2026 UTC, customers hitting the webhooks delivery API may have experienced higher latency or failed requests. During the impact window, 0.82% of requests took longer than 3s and 0.004% resulted in a 500 error response.
Our monitors caught the impact on the individual backing data source, and we were able to attribute the degradation to a noisy neighbor effect due requests to a specific webhook generating excessive load on the API. The incident was mitigated once traffic from the specific hook decreased.
We have since added a rate limiter for this webhooks API to prevent similar spikes in usage impacting others and will further refine the rate limits for other webhook API routes to help prevent similar occurrences in the future.
Feb 27, 00:01 - 00:04 UTC