Updated: Late Tuesday, Google said that an update to its Chrome browser is likely to blame for the issue. Read more about it here.

Film and TV editors across Los Angeles were sweating Monday evening as their workstations were refusing to reboot, resulting in speculations about a possible computer virus attack. Social media reports suggested that the issue was widespread among users of Mac Pro computers running older versions of Apple’s operating system as well as Avid’s Media Composer software.

Avid said in a statement Tuesday morning that it was aware of the issue, and that its engineers had made it a top priority to resolve the cause of it. On Tuesday afternoon, the company followed up with a video featuring its CEO Jeff Rosica and its CTO Tim Claman. Rosica said that the company has working “around the clock, whatever it takes” to solve the issue, and added that company engineers were on site “at a number of sites” to further investigate the problem.

Apple didn’t respond to a request for comment late Monday.

“A lot of L.A. post shops and people out on shows having their Macs slowly crash,” reported video post-production consultant Matt Penn on Twitter.

From what I gather there’s a massive failure of Macs with iLok/Avid that’s happening all over right now. A lot of L.A. post shops and people out on shows having their Macs slowly crash and wont boot again. Engineers are looking in to it. Don’t shut your machine off. #postchat — Matt Penn (@mattpenndotcom) September 24, 2019

Freelance film editor Marcus Pun reposted a message from a popular Avid Facebook user group, advising users not to turn off their workstations.

BIG ALERT tonight regarding #Apple, and #MacOS running on the can. DO NOT SHUT DOWN!! #AvidEditors #Avid Apparently something is corrupting one of the UNIX root level folders. Back up everything, not just on the servers is you are in a connected environment. Refer to below FB pg pic.twitter.com/iLlfHVRfmp — MarcusPun (@MarcusPun) September 24, 2019

Other users reported that multiple computers at their company were affected by the issue, with social media chatter indicating that a number of different companies, and even major shows like “Modern Family,” were affected by the issue.

Some analysis by affected users seemed to suggest that the outage may not have been caused by a virus, but by a recent software update that may have corrupted some data, with some suggesting a OS X reinstall that keeps the existing data to restart the machine.

On Tuesday afternoon, Avid’s Claman suggested that users running Avid should for the time being not reboot their computers, not install any software updates and back up all sensitive data.

Update: This story was updated multiple times throughout the day as new information emerged.