Outage report · Partial outage

Slack outage on Jul 24, 2026

Incident: Issue sending messages to channels via certain Workflows

SeverityPartial outage

StartedJul 24, 2026, 08:22UTC

ResolvedJul 24, 2026, 10:47UTC

Duration2h 24m

What happened

Slack reported a partial outage starting Jul 24, 2026, 08:22 UTC. It was marked resolved at Jul 24, 2026, 10:47 UTC.

The incident lasted 2h 24m from first report to resolution.
Slack had reported 11 other partial or major outages in the 90 days before it.
8 other vendors we track reported a significant incident within 12 hours of it.

Latest update from Slack

1:22am PDT We’re aware of an issue affecting Workflows that include 'refer to a message link'. Users with these workflows are unable to send a message to a channel, and will receive an ‘Input Validation Error’ when trying to perform this step. We’re actively investigating this issue and will provide an update in 30 minutes or sooner if more information becomes available.  1:44am PDT We've engaged our Worklow team to assist in the investigation. Initial analysis appears to show a conflict between specific variables. We’re continuing to work to understand whether this is the trigger of the issue. We’ll provide an update in 30 minutes or sooner if more information becomes available.  2:08am PDT The Workflow team is currently analyzing whether a recent change may have resulted in the conflict between variables that has been observed. It is expected to take some time to validate whether this is the case. We’ll provide an update in 60 minutes or sooner if more information beco

Read Slack's official incident report ↗