Resumo
On February 6, 2026, between 17:49 UTC and 18:36 UTC, the GitHub Mobile service was degraded, and some users were unable to create pull request review comments on deleted lines (and in some cases, comments on deleted files). This impacted users on the newer comment-positioning flow available in version 1.244.0 of the mobile apps. Telemetry indicated that the failures increased as the Android rollout progressed. This was due to a defect in the new comment-positioning workflow that could result in the server rejecting comment creation for certain deleted-line positions.
We mitigated the incident by halting the Android rollout and implementing interim client-side fallback behavior while a platform fix is in progress. The client-side fallback is scheduled to be published early this week. We are working to (1) add clearer client-side error handling (avoid infinite spinners), (2) improve monitoring/alerting for these failures, and (3) adopt stable diff identifiers for diff-based operations to reduce the likelihood of recurrence.