A widespread outage on the video call service Zoom caused problems for students, teachers and professors around the United States on Monday morning, the first day of classes for many schools and universities that are reopening online because of the coronavirus pandemic.

The partial outage, which lasted almost four hours, took place just as working and school hours began on the East Coast and affected the wide variety of people who now rely on Zoom as a lifeline. Businesses could not make video calls to clients, courthouses could not conduct hearings, and city and county governments had to postpone meetings.

Zoom said it began receiving reports of users being unable to start or join meetings at about 8:50 a.m. on the East Coast. About two hours later, the company said that it was “deploying a fix across our cloud,” and at about 12:40 p.m. it said it had resolved the issue.

“Thank you all for your patience and our sincere apologies for disrupting your day,” the company said on Twitter.

The company did not describe the problem except to say it was “causing users to be unable to authenticate to the Zoom website” and unable to start and join meetings. It also said some users were “unable to sign up for paid accounts,” or “upgrade or manage their service on the Zoom website.”

As the coronavirus pandemic has kept students out of classrooms and office workers out of offices, Zoom has become a critical lifeline for many schools, companies and local governments. Michigan’s Supreme Court, which has conducted hundreds of thousands of hearings online since the pandemic began, said Monday that it was among the institutions hit by the outage.


“Virtual courtroom proceedings are being affected by a widespread Zoom outage in the U.S. and beyond that is preventing courts being able to start and join meetings,” the Supreme Court said on Twitter.

The website DownDetector, which tracks outages at social media companies and tech companies, showed significant outages in major cities across the country, including New York, Washington, Atlanta, Chicago, St. Louis and San Francisco. At one point, the site recorded more than 15,000 reports of outages.

By about 10:55 a.m., shares in Zoom had fallen about 2.7%, though they began to recover as service was restored.

In a typical year, nearly two-thirds of the 50 million public schoolchildren in the United States have returned to their classrooms b the third week of August. This year, many of the country’s largest districts have delayed the start of school or have chosen to begin the year with remote learning as the coronavirus continues to spread.

Zoom has proved invaluable for many schools, letting classes continue without students and teachers packed into classrooms. During the outage Monday, schools in Georgia, Texas and Pennsylvania reported problems. The Atlanta school district, which serves about 50,000 students, was among those affected by the outage. “We are working to resolve the issue and will provide an update when restored,” the district said on Twitter on Monday morning. “Parents and students will hear from their local school regarding next steps and alternative ways for virtual learning.”

Students and professors at Penn State University reported a “widespread outage” of Zoom service on its campus Monday morning, and urged students to download Zoom’s desktop client as a possible workaround.

Hundreds of millions of people now use Zoom, up from about 10 million in 2019. Like other tech companies that have experienced sudden popularity, Zoom has scrambled to scale up its capabilities and security. In April, Zoom formed a council of chief information security officers from other companies to share ideas for improving quality and minimizing disruptions.