Wednesday May 22, 2019


Some customers were unable to @mention user groups

Issue Summary:

Starting May 22, 2019 at 5:12 p.m PDT till 10:23 a.m PDT on May 23, 2019 a subset of our users were unable to successfully @-mention user groups.

During our investigation we realized these issues were caused by a change made a few days prior. We had enabled a feature on our end that caused a caching issue which affected user groups. Our engineering team then implemented a fix that resolved the issue.

We’re hard at work on scoping preventative measures to ensure this doesn’t happen again in the future.

6:30 PM PST

We've got good news: we're in the clear and all @-mentions should now work correctly. We're sorry for any trouble this caused and please drop us a note at if you're still having issues.

10:55 AM PST

We're seeing positive signs that user group mentioning is restored for all customers after refreshing Slack. We'll continue to monitor the issue. Please contact if you are still seeing troubles with @-mentions.

8:55 PM PST

We've identified the issue and are working to restore the ability to @mention user groups for all customers. If you are affected, please try refreshing Slack (Ctrl+R or Cmd+R) to see these changes.

8:25 PM PST

No new updates to share, but our teams are still digging into why some customers cannot @mention user groups.

7:47 PM PST

We're continuing to investigate the issue with user groups, but we don’t have new information just yet. Thanks for bearing with us.

7:14 PM PST

Some of our customers are unable to @-mention user groups in their workspaces. We're currently looking into this, and we'll keep you posted when we find out more. We're sorry for the disruption.

6:44 PM PST

Some people may be having an issue with Slack. We’re currently investigating and will have more information shortly. Thank you for your patience.

6:38 PM PST

Services affected