MENLO PARK (CBS SF) — A massive outage that knocked out access for millions of Facebook, Instagram and Messenger users was caused by a “server configuration change” and not a cyber attack, the Bay Area social media giant announced Thursday.

The issued began around 9 a.m. PDT Wednesday and according to Downdetector.com was spread across the East and West Coast of the United States, parts of Europe and elsewhere.

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“Yesterday, as a result of a server configuration change, many people had trouble accessing our apps and services,” Facebook said in a post. “We’ve now resolved the issues and our systems are recovering. We’re very sorry for the inconvenience and appreciate everyone’s patience.”

Instagram was back in action at 9:41 p.m. PDT on Wednesday with Facebook taking a few more hours to return to normal access.

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Via its Twitter account, Facebook said on Wednesday that the outage was not due to a “distributed denial of service” or DDoS attack, a type of attack that hackers use to interrupt service to a site.

The outage was the longest in the company’s history and many people vented about it Facebook’s competitor Twitter.

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It appears users all over the world reported problems. Users also reported problems with Instagram, which is owned by Facebook.