On 19 July, a number of airlines, banks and other institutions around the world experienced a disruption. In particular, flights of several major US airlines, including Delta, United and American Airlines, were postponed due to communication problems.
This was reported by the Federal Aviation Administration, CNN reports.
The suspension of some airlines came after a significant disruption in Microsoft's operations on Thursday.
Other carriers, including Allegiant and SunCountry, reported difficulties, including with online booking, check-in and travel management functions.
Microsoft said on its website that service to some customers in the central United States has been interrupted, ‘including disruptions to service management operations and connectivity or service availability’.
The company said it had identified the cause and was working to resolve it. A company spokesperson did not immediately respond to a request for comment.
Oleh Horokhovskyy, co-founder of Ukrainian monobank, said that a global IT failure has occurred worldwide, linked to the interaction between Crowdstrike antivirus and Windows. Crowdstrike, a US-based cybersecurity company, has admitted responsibility for the error and is working to fix it.
In Ukraine, Nova Poshta and Sense Bank reported outages.
The BBC reports chaos at Sydney airport. Reports of failures are coming in from all over the world. Broadcasters, including the UK's Sky News, have also reported problems. Several airports across the grid reported flight delays. In Australia, the disruption affected airports and shops, and in the UK, railways.
In total, more than 1,000 flights were cancelled worldwide due to today's incident.
The Baltic Hub port terminal in Poland was also affected.