That reply looks as though it was prepared by AI. These articles may help. You should backup data including exporting logins. https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data https://support.mozilla.org/en-US/kb/recover-lost-or-missing-bookmarks ---- https://support.mozilla.org/en-US/kb/export-firefox-bookmarks-to-backup-or-transfer https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles