On what is for many Americans their first day back to work in 2021, major workplace communication platform Slack was reportedly down for many users across the U.S. for most of the day Monday.

Outage reporting site Downdetector had fielded at least 16,000 reports of outages by about 9 a.m. ET Monday, but Slack is reporting that a hard refresh of the app has resolved the connection issues. The Slack status update has advised users to select CTRL/CMD on their keyboard, + R to refresh Slack on their desktop.

“We’re seeing improvements with error rates on our side, and we believe affected customers should be able to access Slack. We’re continuing to work to resolve the trouble with calendar apps and email notifications,” a statement from the company read about 2:30 p.m.

The collaboration platform for workplace teams at various national companies reportedly has more than 12 million daily active users as of 2019, according to a Business of Apps report.

Earlier Monday morning, the company posted an update on its Status website noting the issues that had been reported by users.

“Customers may have trouble loading channels or connecting to Slack at this time. Our team is investigating and we’ll follow up with more information as soon as we have it. We apologize for any disruption caused,” a message read about 10:44 a.m.

The company promised to update its site with status reports every 30 minutes until the issues are resolved. According to the Downdetector live outage map, Slack users in New York, Atlanta, San Francisco, Boston, St. Louis and Houston were reporting the most issues with the site.

Internet service outages are not uncommon, are usually resolved relatively swiftly and are only rarely the result of hacking or other intentional mischief. Google went down briefly in December, with people in several countries briefly unable to access their Gmail accounts, watch YouTube videos or get to their online documents during an outage. In August, Zoom went down briefly just as many students were beginning the school year at home. And, in September, Microsoft services had an outage that lasted for five hours.

The Associated Press contributed to this report.