Slack has stopped working for some users, leaving them unable to get into their virtual workplaces.
Users reported they were unable to load the app, and that messages were not being sent or received.
The partial outage happened just as the working day began in the US, and in the middle of the afternoon European time.
On its website, Slack said it was aware of the issue and looking to find the cause.
“We’re investigating the issue where Slack is not loading for some users,” it wrote. “We’re looking into the cause and will provide more information as soon as it’s available.”
Not everyone seemed to be affected by the problems, however, with some able to message as normal.
The outage came just 12 hours after another major outage on the service, which lasted for around an hour. During those problems, Slack users were hit by the same errors.
The company said in an update on its status page that those problems were caused by a “code change” that “inadvertently caused a conflict in the desktop app and web client, preventing a small number of customers from sending messages”. It changed that code back and should have restored service, it said then.