Changes / GitHub Copilot / Copilot Code Review is unable to complete reviews

GitHub Copilot: Critical incident: Copilot Code Review is unable to complete reviews

Summary

GitHub Copilot reported a critical Code Review outage starting 2026-09-28 21:16 UTC, resolved at 2026-09-28 22:08 UTC (51 min). Approximately 70% of requested reviews failed across all environments; failed reviews were not automatically retried, so users needed to re-request them from their pull requests. GitHub attributed the issue to a dependent-service change and reported a rollback underway.

Machine-written from the diff below (Sol; type: incident outage). Check the diff before relying on it.

Major incidentLabel: outage (model (Jev), 41%)Changed Detected Source: stspg.io

What changed

AddedTitle#1
Before: not present
After: Copilot Code Review is unable to complete reviews
AddedImpact#2
Before: not present
After: critical
AddedStatus#3
Before: not present
After: resolved
AddedStart time#4
Before: not present
After: 2026-09-28 21:16 UTC
AddedResolved time#5
Before: not present
After: 2026-09-28 22:08 UTC
AddedUpdateinvestigating#6
Before: not present
After: We are investigating reports of impacted performance for some GitHub services.
AddedUpdateinvestigating#7
Before: not present
After: Revert of the impacted change is in flight, expect full recovery once the deployment is done.
AddedUpdateinvestigating#8
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After: Copilot Code review has recovered, for reviews that were previously not successful you can re-request review from your PR.
AddedUpdateresolved#9
Before: not present
After: On September 28, 2026, between 19:23 UTC and 22:08 UTC the Copilot Code Review service was degraded and pull request reviews did not complete in all environments. On average, approximately 70% of requested reviews did not complete. Reviews requested during this window were not automatically retried, and users needed to re-request a review from their pull request. This was due to a change in a dependent service that stopped delivering data Copilot Code Review needs to complete a review. Review completion is an inherently delayed signal, because each review job takes time to start and finish, so it took longer to detect the impact.<br /><br />We mitigated the incident by reverting the change.<br /><br />We are working to add a faster signal for reviews that fail to complete, add deployment validation that confirms a Copilot Code Review completes end to end, improve how we track internal dependencies between services, and make our deployment pipeline more reliable to reduce our time to detection and mitigation of issues like this one in the future.

First version of this incident archived by Rewindex. View the live incident.

History of this incident

When (UTC)ChangeKind
Critical incident: Copilot Code Review is unable to complete reviews (this change)
GitHub Copilot reported a critical Code Review outage starting 2026-09-28 21:16 UTC, resolved at 2026-09-28 22:08 UTC (51 min). Approximately 70% of requested reviews failed across all environments; failed reviews were not automatically retried, so users needed to re-request them from their pull requests. GitHub attributed the issue to a dependent-service change and reported a rollback underway.
Major incident

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