Look on your desktop. Do you see a folder called; '''Old Firefox?''' Look inside. Look for the folder with the latest creation date. https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles https://support.mozilla.org/en-US/kb/how-run-firefox-when-profile-missing-inaccessible

The System Details list shows you run an older Firefox 55 version that is no longer supported with security updates. Please update to the current Firefox 64.0 release. *Help -> About Firefox *https://support.mozilla.org/en-US/kb/update-firefox-latest-version ---- Did you look for backups in the bookmarkbackups folder? *Bookmarks -> Show All Bookmarks -> Import & Backup -> Restore *https://support.mozilla.org/en-US/kb/restore-bookmarks-from-backup-or-move-them Note that Sync isn't meant to be used as a backup. *https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles