The messaging service championed by Silicon Valley startup teams is experiencing a major outage, posting a "server error" message when people try to access the platform.
"We're sincerely sorry for the service disruption you're seeing at the moment. We're working on it with top priority," Slack said in a tweet.
We're sincerely sorry for the service disruption you're seeing at the moment. We're working on it with top priority: https://t.co/hlhV4ZiG7E— Slack (@SlackHQ) October 31, 2017
We're doing all we can to get this issue resolved. Again, we're so very sorry for the trouble. Thanks for being patient with us.— Slack (@SlackHQ) November 1, 2017
The outage is leaving users unable to chat and send files digitally across their workplaces. Its services, often used by company teams, can be used across multiple devices and platforms and allow users to chat in groups, one-to-one, or send messages to a chat with themselves where they can post work reminders.
The cloud-based software was released in 2013 and is now estimated to have more than 6m daily users globally.
Last month, Softbank's Vision Fund led a $250m (£188m) investment in the US tech firm which values it at $5bn.
For now, at least, users are having to get re-acquainted with their work colleagues in person:
Me, 5 minutes into the Great Slack Outage of 2017: pic.twitter.com/AXP2MRRB4Y— 🌻 Cass 🌻 (@cee_jade) October 31, 2017
Trying to communicate via email while Slack is down. pic.twitter.com/TcR7fgoZQK— Richard James (@richjamesuk) October 31, 2017
tfw you wanna slack your coworkers a funny tweet about Slack being down, but SLACK IS DOWN!!! pic.twitter.com/COZjtjcx3k— Rachel Heine @ SDCC (@RachelHeine) October 31, 2017