Hi, don't close your Firefox. When you say you were "in" Firefox Sync, I'm not sure where you were editing. '''If you deleted Bookmarks in your current installation of Firefox:''' Try the "Undo" feature in the Library window: menu button > Bookmarks > Manage Bookmarks then: Organize > Undo As with text editing, you may need to Undo multiple times to roll back individual edits to the point you're looking for. If Firefox was already closed and reopened, that won't work. Next thing would be to restore a backup: (1) EXPORT the bookmarks you have now so you can keep it for reference on other edits/changes. [[Export Firefox bookmarks to an HTML file to back up or transfer bookmarks]] After creating the bookmarks.html file, open it in a tab to confirm that the export worked. (2) RESTORE the last automatic backup using the steps in this article: [[Restore bookmarks from backup or move them to another computer]] Any progress so far?

More generally: to reopen a closed tab, either: * Ctrl+Shift+T * menu button > History > Recently closed tabs * (menu bar) History > Recently closed tabs