(The Center Square) – Zoom, a digital video platform that many schools across the country have adopted to conduct remote classes, is experiencing an outage Monday as the new school week begins.

"We have received reports of users being unable to visit the Zoom website (zoom.us) and unable to start and join Zoom Meetings and Webinars," Zoom announced on its website. "We are currently investigating and will provide updates as we have them."

School districts alerted students and parents of possible alternative methods of communication while Zoom is down.

"We have confirmed that Zoom is currently experiencing a wide-spread outage due to a recent system upgrade," School District 155, in the northwest suburbs of Chicago, wrote in an email to students and parents. "Students should check Canvas for announcements from their teachers which may include invites to Google Meet/Hangouts."

Later Monday, Zoom said it had fixed the issue.

“We have resolved an issue that caused some users to be unable to start and join Zoom Meetings and Webinars or manage aspects of their account on the Zoom website," a company spokesperson said. "We sincerely apologize for any inconvenience.”

ZDNet.com reports the outage is mostly affecting the eastern U.S. and Great Britain.

The platform is also popular with businesses.