Facebook Inc blamed a “faulty configuration change” for a nearly six-hour outage on Monday that prevented the company’s 3.5 billion users from accessing its social media and messaging services such as WhatsApp, Instagram and Messenger.
The company in a late Monday blog post did not specify who executed the configuration change and whether it was planned.
Several Facebook employees who declined to be named had told Reuters earlier that they believed that the outage was caused by an internal mistake in how internet traffic is routed to its systems.
The failures of internal communication tools and other resources that depend on that same network in order to work compounded the error, the employees said. Security experts have said an inadvertent mistake or sabotage by an insider were both plausible.
“We want to make clear at this time we believe the root cause of this outage was a faulty configuration change,” Facebook said in the blog.
The Facebook outage is the largest ever tracked by web monitoring group Downdetector.