Facebook Inc. believes a ‘faulty configuration change’ on its routers caused a global outage for almost six-hour on Monday, Oct. 4. This outage affected close to 3.5 billion users of products of Facebook, such as Facebook, Instagram, WhatsApp and Messenger. Along with the products, the outage took out Facebook’s internal software for the employees that run the offices.

Millions of users of Facebook, WhatsApp, Messenger and Instagram around the world, described outages last evening. It prompted Facebook to go to Twitter to acknowledge the issue and tell users to wait as they started working immediately to resolve issues. Facebook issued an apology to its users for the outage. Facebook especially apologized for the effect of the outage on businesses that run on several of its platforms for sales. They also thanked the users for bearing with them.

According to reports pouring in from all over the world, several tools which run on Facebook services were down due to the outage. This includes all the Facebook employees’ work passes and official email account, and the AR/VR products like Oculus VR, and Pokémon Go, which need a login via Facebook, as reported by Reuters.

Around 50,000 reports by users globally were submitted to DownDetector to figure out if Facebook was down or not before 5:00 p.m. 72% percent of the problems of the complaints submitted to DownDetector were with the Facebook website itself. Some complaints were made regarding the server connection as well as the app. Regarding WhatsApp, more than 75,000 complaints were registered, and regarding Instagram 30,000 complaints were registered. Many users stating the issue as server connection. DownDetector reported that it was one of the biggest ever outages they tracked, as reported by Gadgets 360.

Eventually, Facebook and Instagram were back up on Monday evening. WhatsApp became available in the early morning of Tuesday, Oct. 5. Facebook incurred losses of around $545,000 in ad revenue per hour of the global outage, according to ad-measurement firm Standard Media Index.

Facebook has offered to reason for the outage. In a statement, they said that their engineering teams have figured out that the configuration changes on the routers caused the outage which disrupted global communication. This interruption to network traffic had a domino effect on the way their data centers work, which stalled their services.

Facebook In this photo illustration, a smart phone screen displays the logo of Facebook on a Facebook website background, on April 7, 2021, in Arlington, Virginia - Facebook usage has held steady in the United States despite a string of controversies about the leading social network, even as younger users tap into rival platforms such as TikTok, a survey showed Wednesday. Photo by OLIVIER DOULIERY/AFP via Getty Images