Hi sb9493, can you describe the situation in more detail -- for example: (A) You let Firefox up to Firefox 78 just like always, but bookmarks were missing after it restarted. Nothing unusual happened. ''Are you able to restore bookmarks from a backup using the steps in this article:'' [[Restore bookmarks from backup or move them to another computer]]? (B) Firefox said it would speed up by resetting a few things, but then personal data was missing, too. And now there is a folder on the desktop named Old Firefox Data. (Refresh scenario) (C) Firefox has different data if you start it from its own program shortcut or from a URL on the desktop or in another program. (Possible dual install scenario) More information would be helpful in pointing toward a particular next step.