Slack down: Chat app stops working in the middle of the day, leaving colleagues unable to chat

Slack, the popular workplace chat app, has broken in the middle of the day.

The outage means that colleagues are unable to talk to each other. Attempting to send messages showed an error that indicated they had not been delivered – though users were still able to see old conversations.

Many of the world’s biggest companies rely on Slack to connect colleagues both within and across companies. As many workplaces have gone at least partly remote, it is now a significant part of workplace communication.

The outage began around 10am UK time on Thursday. Tracking website Down Detector showed a rapid spike in the number of reports of problems.

The official Slack status page was not initially updated even as the outage began. It had also not posted on its official Twitter accounts, which it sometimes uses to provide updates on outages.

But at 10.35am UK time, more than half an hour after the outage began, it said that it was aware of the issues – but not what was causing them.

“Users may be experiencing trouble with sending messages in Slack,” the message on its official status page read. “We’re investigating and will let you know as soon as we know more. We appreciate your patience in the meantime.”

Some 20 minutes later, it posted another update, which suggested the issue was worse than the company had initially feared

“Slack experiencing an outage across the app. Users may be experiencing trouble with sending messages, using workflows and various other actions in Slack,” it wrote.

“We’re investigating and will let you know as soon as we know more. We appreciate your patience in the meantime.”

Around an hour later, service appeared to have been restored, with Slack users able to post and see messages once again.