Outage in Slack
Users May Not Receive Notifications on Slack Thread Replies
Resolved MinorIncident Report
Summary AI Generated
Slack experienced a notification system issue where users were not receiving notification banners for thread replies, with some users also reporting login difficulties and message sending problems. The incident affected Slack's notification functionality for 3.5 hours. The issue was traced to a recent deployment, and Slack resolved it by rolling back the problematic deployment after successful testing in their test environments.
Some users have reported issues with thread replies not generating a notification banner. We’re investigating the issue, and have identified a recent deployment as a possible trigger.
We apologize for the inconvenience and will report back as more information becomes available.
Components affected
Slack NotificationsTrusted by 1,000+ teams
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Latest Updates ( sorted recent to last )
22 days ago - at 04/27/2026 06:07PM
We’re observing positive signals after rolling back the deployment in test environments. We will complete some final validations before rolling back the deployment in the production environment.
Thank you for your patience as we work through this one. We’ll report back once production rollback is completed or if there are substantial updates to share.
22 days ago - at 04/27/2026 05:11PM
Some users have reported issues with thread replies not generating a notification banner. We’re investigating the issue, and have identified a recent deployment as a possible trigger.
We apologize for the inconvenience and will report back as more information becomes available.
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