"Some workspaces might be experiencing issues with messages sending and loading. Our team is on the case," a Slack notice read. "We'll report back once we have an update to share."
"People are sending things once but it's coming up 2-3 times," one Slack user complained on Twitter as the workplace chat app went into meltdown.
Numerous social media users claimed messages were not being sent.
Slack said it was working to fix the issues as quickly as possible.
Outages have been reported at the popular workplace chat application, with messages not being sent.
"We're sorry for the trouble today. Our team is investigating now. We'll have things back to normal ASAP!" the company said on Twitter.
The social media giant's scale may be enough to swamp smaller upstarts in the workplace communications space.
The tech giant is looking to reach beyond its approximately 1.35 billion monthly active users.