On Monday, social media users went into meltdown when Instagram, Facebook and WhatsApp all stopped working.
All three Facebook-owned sites went down at around 5pm GMT and remained completely unusable until at least 11pm.
The error was experienced worldwide, with users unable to view posts, read messages or refresh their newsfeed for almost six hours.
It’s one of the worst social media outages the world has ever seen, and many thought that the platforms had disappeared forever.
So, why did Instagram, Facebook and WhatsApp go down yesterday?
Facebook blames “configuration changes” for the outage
After the apps and websites began working as normal again, Facebook released a statement apologising and explaining exactly what happened.
“We are sorry for the inconvenience caused by today’s outage across our platforms. We’ve been working as hard as we can to restore access, and our systems are now back up and running,” they said.
Facebook then revealed that the sites went down due to a “faulty configuration change,” writing:
“Our engineering teams have learned that configuration changes on the backbone routers that coordinate network traffic between our data centers caused issues that interrupted this communication.”
“This disruption to network traffic had a cascading effect on the way our data centers communicate, bringing our services to a halt,” they continued.
Why did it take so long to fix?
Usually when Instagram, Facebook or WhatsApp go down, Facebook quickly diagnoses the problem and begins working on a fix.
However, this time, that process seemed to take a lot longer than usual, resulting in outages of six to seven hours.
In the same statement, Facebook revealed the reason why it took so long to fix, writing:
“The underlying cause of this outage also impacted many of the internal tools and systems we use in our day-to-day operations, complicating our attempts to quickly diagnose and resolve the problem.”
They added that despite this, there is no evidence that any user data was compromised during the downtime.
Mark Zuckerberg apologises
Alongside the public statement, Facebook CEO Mark Zuckerberg also made a personal apology.
On his Facebook page, he wrote: “Facebook, Instagram, WhatsApp and Messenger are coming back online now. Sorry for the disruption today — I know how much you rely on our services to stay connected with the people you care about.”
Instagram CEO Adam Mosseri apologised too, writing on Twitter: “Apologies for the outage today, this wasn’t how we wanted to start the week. Instagram should be slowly coming back online now.”
Facebook says it is now working to understand more about the outages that happened on October 4th in order to make its infrastructure more “resilient” and prevent future downtime.