Many of founder Mark Zuckerberg's old posts have vanished from Facebook, and won't be restored.
Some were a record of key moments in the company's history.
Their absence was first noted by Business Insider, which was told by the social network that the posts were "deleted due to technical errors".
Facebook will not try to retrieve them because the process would be too complicated and not guaranteed to work, the company said in a statement. While Facebook backs up data, it has changed its archive system along the way.
The company could not say how many of Zuckerberg's posts had been deleted.