Slack has stopped working properly, just as many people have returned to their real and virtual offices after the break.

Users couldn’t reliably send or receive messages, with chats popping up to work and then crashing. The text will appear to send but then greyed out within the chat, indicating that it hasn’t actually been delivered.

Down Detector’s website tracking website has shown a surprising rise in reports of messaging app issues.

It also appears that some parts of the Slack website are inaccessible.

But the company’s official Twitter account and server status page didn’t immediately register any problems.

It was later updated to clarify that the company was aware of the issue and working on it.

Clients may be having trouble contacting Slack to download channels at this time. Slack wrote on Twitter: “Our team is on the issue and will keep you informed. “We apologize for any inconvenience caused.”

The company gave no indication that it was aware of the cause of the problem, or any indication of when internet connectivity would return.

Slack – along with competitors like Zoom and Microsoft’s Teams Group – has become a key part of the business through the shutdown, as workplaces look to allow their employees to communicate while discouraging them from going to the offices.

This means that any disruption can have an immediate and significant impact, with employees not being able to communicate as usual.