A faulty update knocked out several Windows computers and servers around the world on July 19, sending them through a bootloop featuring a so-called blue screen of death, disrupting aviation, banking, telecommunications, hospitals, TV channels and other companies around the world.

The update was part of the Falcon endpoint threat detection and response product developed by Crowdstrike, an Austin, Texas-based cybersecurity firm.

Flights were briefly grounded in the United States, with airports reeling under a complete collapse of their digital systems around the world. In India, airlines started checking passengers in manually at airports serving Bengaluru, Chennai, New Delhi, Hyderabad, Kochi, Thiruvananthapuram and Mumbai, among others, issuing handwritten boarding passes as blue error screens took over flight information display boards. Many flights were delayed for hours or cancelled, with IndiGo alone reporting that it had cancelled at least 283 trips on Friday and Saturday due to the outage.

The Union government’s eOffice suite for processing files and paperwork was also impacted for two hours, according to a source. Minister of Electronics and Information Technology Ashwini Vaishnaw said that the National Informatics Centre was not impacted.