In a tweet on Thursday, Facebook blamed the outage on "a server configuration change."
"We've now resolved the issues and our systems are recovering," Facebook said. "We’re very sorry for the inconvenience and appreciate everyone’s patience."
On Wednesday, network management firm Netscout blamed the issue on a separate cause — a type of routing issue known as a Border Gateway Protocol (BGP) leak. However, other firms said they didn’t think a BGP problem was to blame, and Netscout later walked back its claim.
“Absent more forensic evidence, we can’t speculate about the cause of that specific outage,” said the company in an email.
Editor's note: This story has been updated to reflect Facebook's statement and the fact that Netscout walked back its claim after other firms cast doubt on its analysis.