Facebook, Instagram and WhatsApp have been fully reconnected after a six hour outage last night.
The blackout was caused by an internal technical issue, which affected the entire group of apps.
The platforms were down from 4pm Irish time until around 10pm, causing major disruption to businesses and advertisers.
In a statement, Facebook said that the faulty configuration change affected the company’s internal tools and systems which complicated attempts to resolve the problem.
The incident was one of the worst outages in the history of Facebook. The company has apologised for the outage and the effect it had on millions of users.