Videoconferencing platform Zoom experienced worldwide outages Monday morning, coinciding with the first day of remote classes for many schools and universities.

On its status page, Zoom reported partial outages for its website, meetings and webinars. By Monday afternoon, all systems were reported as operational.

Downdetector recorded a spike in issue reports, mostly from North America and western Europe, which peaked at nearly 17,000 complaints at 9 a.m. EST.

Lighter areas on Downdetector’s map Monday morning also showed complaints in China, India, Mexico and other countries, although most had faded by the afternoon.

The company’s Twitter mentions were flooded with concerned and panicked users, including professors and students.

“Please fix the system — we depend on your availability,” wrote Janine M. Ziermann, an assistant professor at Howard University’s College of Medicine in Washington.

“Half of my student's [sic] don't get emails due to server failure ... Zoom seems down ... my lecture starts in 43 minutes,” she wrote, alongside an animated image from TV show The Big Bang Theory of a character hyperventilating into a paper bag.

Half of my student's don't get emails due to server failure ... Zoom seems down ...
my lecture starts in 43 minutes pic.twitter.com/OY2sPRyx5g

— Janine M. Ziermann, PhD (@JMZiermann) August 24, 2020

“My laptop is buzzing, phone melting down,” wrote Florida State University professor Mark Zeigler. “I would cry, but I decided to laugh and have a cup of tea.”

So ZOOM is out campus wide. My laptop is buzzing, phone melting down....I would cry, but I decided to laugh and have a cup of tea.

— Mark Zeigler (@fsuzeigler) August 24, 2020

Students were quick to make jokes on the widespread outages.

“And like clockwork both Zoom and Canvas crash the first morning back to school,” wrote Lauren Gruber, a graduate student at Indiana University, alongside an image of a flaming Elmo figure. The meme is used to denote chaotic situations. “You really, really can’t make this stuff up.”

And like clockwork both Zoom and Canvas crash the first morning back to school. You really, really can’t make this stuff up. pic.twitter.com/u3SCCjIliZ

— Lauren Gruber (@GrubersOrch) August 24, 2020

Canvas is a program that supports online learning by allowing users to submit homework assignments and view their grades.

Zoom announced it was investigating the problems at 8:51 a.m. EST and said by 11:30 a.m. it had rolled out a fix for most users.

“Everything should be working properly now!” the company tweeted, offering its “sincere apologies” to customers.

Everything should be working properly now! We are continuing to monitor the situation. Thank you all for your patience and our sincere apologies for disrupting your day.

— Zoom (@zoom_us) August 24, 2020

Users in California, Mexico and elsewhere replied saying they were still experiencing issues. Others, seemingly students, jokingly asked Zoom to shut down again.

Billionaire businessman Eric Yuan started Zoom in 2011, originally under the name Saasbee. By the end of its first month, the California-based company had more than 400,000 users, and by 2017 was valued at $1 billion. The company remained little known outside its base of mostly business users, but when the coronavirus pandemic began in early 2020, Zoom saw its usage rates surge.

Schools, universities and other organizations took their operations to Zoom, kicking off heightened scrutiny of the software’s security and privacy features, and connections to China.

In June, the company acknowledged temporarily closing three accounts belonging to U.S.-based Chinese activists after they held a Zoom event to commemorate the 31st anniversary of the Tiananmen Square crackdown, Axios reported.

Zoom has also been plagued by reports of unwanted guests intruding on video meetings, an event so common it has its own name: Zoom-bombing. The Federal Bureau of Investigation issued a press release in March warning the public of the practice after two schools said their online classes were hacked.

The widespread crashes Monday morning underscored the problems of online learning, even as schools kick off another year.