Air travel, banking, media and hospital systems were just some of the industries affected by a bug in a software update that scrambled business operations for many globally on Friday, July 19, with ongoing ripple effects into the new week.

Many of those who use Microsoft Windows were likely to have experienced a “blue screen of death” or an error page. The issue was reportedly due to a single bug in a software update from cybersecurity company CrowdStrike, which provides antivirus software for Microsoft users.

Redmond, WA-based Microsoft [Nasdaq: MSFT] said Monday, July 22, that about 8.5 million Windows devices were affected by the faulty software update that caused widespread disruptions globally. It had earlier reported that an update to its “Falcon Sensor” software was what was causing Microsoft Windows to crash.

CrowdStrike President and CEO George Kurtz released a series of statement centering on the incident not being a security concern or a cyberattack. He added early on that the issue has been identified and that the company has been deploying a fix.

“We refer customers to the support portal for the latest updates and will continue to provide complete and continuous updates on our website,” Kurtz said.

The bug was causing major delays and cancellations at airports across the globe. Flight tracking data site FlightAware noted nearly 24,000 delays and 2,300 cancellations globally by 9:30 a.m. July 19. While some airlines have been able to resume operation of their digital systems, others are finding analogue solutions in the meantime.

The U.S. Department of Transportation said it was monitoring the situation and suggested those experiencing travel delays and cancellations to use its FlightRights.gov website to help navigate their delays in travel.

Some states’ 911 and non-emergency lines were experiencing issues, including Alaska, Virginia and New Jersey.

New Jersey Governor Phil Murphy released a statement early Friday morning saying that the state had activated its State Emergency Operations Center in response to the disruptions and has provided guidance to other agencies about how to work through the situation.

“We are also engaging county and local governments, 911 call centers, and utilities to assess the impact and offer our assistance.,” he said.

Microsoft released a trouble-shooting guide on X early Friday morning.

Speaking to the hosts of Today this morning, Kurtz said he was “deeply sorry for the impact we’ve caused to customers, to travelers, to anyone affected.” He said some customers have been able to reboot and are seeing progress getting online, and that trend will likely continue throughout the day.

Effects from the global IT outage continued to be felt throughout Friday and into Monday, July 22, especially by government systems and transportation hubs.

Kurtz released a series of statements on X, reiterating that the outage was not a security breach.

“We understand the gravity of the situation and are deeply sorry for the inconvenience and disruption,” he said. “We are working with all impacted customers to ensure that systems are back up and they can deliver the services their customers are counting on.”

Kurtz said the company is working on a “technical update and root cause analysis” that they will share with customers, and shared a letter that was sent to customers and partners.

“We know that adversaries and bad actors will try to exploit events like this. I encourage everyone to remain vigilant and ensure that you’re engaging with official CrowdStrike representatives.”