A worldwide technology outage is affecting everything from personal computers to major businesses Friday morning.

Users of Microsoft365 reported outages that have now taken down personal computers, airlines, media companies, banks, and telecom firms around the world. The software giant stated it was aware and working to resolve a problem “impacting users’ ability to access various Microsoft 365 apps and services.”

On Friday morning, Crowdstrike, a U.S. firm that advertises being used by over half of Fortune 500 companies, said one of its recent content updates had a defect that impacted Microsoft’s Windows Operating System.

Here’s what we know so far about the outage and what is being affected.

What is Crowdstrike?

Crowdstrike is a U.S. firm that launched in 2012 and currently has the “world’s most advanced cloud-native platform that protects and enables the people, processes and technologies that drive modern enterprise,” according to the company’s website.

Was the Microsoft outage a cyberattack?

After Crowdstrike stated that it was a defect in an update if also added that the incident was “not a security incident or cyberattack.”

“The issue has been identified, isolated and a fix has been deployed,” said a statement from Crowdstrike. Microsoft, meanwhile, said “the underlying cause has been fixed,” but that residual impacts continue to affect some of its Microsoft 365 apps and services.

What caused the Microsoft365 outage? What is happening?

The blue screen of death.

We all know it and according to an alert sent by Crowdstrike to its clients and reviewed by Reuters, the company’s “Falcon Sensor” software is causing Microsoft Windows to crash and display a blue screen.

Why are planes grounded? Airports affected across Tennessee, U.S.

According to reports and social media posts from airports across Tennessee and the United States, hundreds of flights were canceled Friday morning. Spirit, American Airlines, Delta Airlines and United Airlines were among those who grounded or canceled flights on Friday morning, disrupting travel plans for thousands.

More than 600 flights were canceled and more than 900 delays were reported as of 5:45 a.m. CT, according to flight-tracking website FlightAware.

Airports across Tennessee have been impacted by the outage. Passengers should check with their airlines to see if their flights have been affected.