Slack, the widely used messaging platform, had a disruption on Monday as many U.S. employees returned to work after the holidays.

The company called the service issue an “incident” in a statement on its website. “Customers may be having problems loading channels or connecting to Slack right now,” the statement said. “Our team is investigating and we will provide more information as soon as we have it. We apologize for any disruptions. “

The Downdetector website, which records Internet disruptions, saw an increase in reported problems with Slack around 10:00 AM East Coast time. The company released its statement on the issue at 10:14 am. Problems included loading channels and sending messages to the service.

Half an hour later, the company said it was still investigating. “There is no additional information to share yet,” it said.

Slack has become an indispensable tool in the workplace over the past few years. More than 10 million users, including many in media organizations and businesses, who work from home due to the coronavirus pandemic. More than 750,000 companies use the service, according to the company, which became an independent publicly traded company in mid-2019.

Salesforce, a company that sells marketing and sales software, announced in December that Slack would buy in for $ 27.7 billion in cash and stocks. This is the latest in a number of major deals that show the need for tools that people can use remotely. Adobe announced in November that it plans to acquire management software company Workfront for $ 1.5 billion, and Atlassian, which sells tools for developers, announced that it would acquire business services company Mindville for an undisclosed amount to buy.