The company said that a "configuration change" had impacted users globally.
It added that the incident was not related to the outage that saw its products taken offline for over six hours earlier this week.
Its Facebook, Instagram, Messenger and Workplace products had been affected, it said.
"We're so sorry if you weren't able to access our products during the last couple of hours," the company said it a statement on Friday evening. "We know how much you depend on us to communicate with one another. We fixed the issue - thanks again for your patience this week."