Backbone router setup mistake caused worldwide Facebook outage

Around 11:50 p.m. CEST on Monday, Facebook's global outage was mostly resolved. After over six hours, Instagram, WhatsApp, Facebook, and Messenger are back online. The failure was caused by an improper update setting, the company claims.

During the downtime, almost 3.5 billion users lost access to their data. By Monday night, Facebook's services had gradually returned. Instagram, Facebook, and WhatsApp are now working for most. The apps may still be unreliable in the future due to simultaneous connections from several devices. Around 4 a.m., WhatsApp CEO Will Cathcart announced on Twitter that everyone could use the service again.

CEO Mark Zuckerberg apologized via Facebook. "Sorry for any inconvenience today, because I know how much you rely on us to keep in touch with the people you care about."

Facebook said the incident occurred while updating its systems. Facebook's router system has a bug that prevented servers from communicating. "We suspect the reason of the outage was a bad configuration," the business claimed.  Facebook says it has no indications that data has also been leaked due to the outage. The problems also prevented employees from accessing the internal systems.