I see three profiles listed in the screenshot. An old 4cayblil.default profile (last used 04.06) that was likely replaced by a new dedicated profile 2nsvjtmx.default-release profile (last used 05.06) when you updated to Firefox 67. Then a new wt03pnep.default profile has been created probably because you noticed that you had switched to the default-release profile. If you lost personal data then look in the oldest profile (4cayblil). *https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile Firefox 67 and later can use a dedicated profile for each of the Firefox update channels and will lock the profile, so it can only be used by Firefox in a specific installation folder. For Release versions this profile would be a xxxxxxxx.default-release profile, profiles used in older Firefox versions usually used a xxxxxxxx.default profile (a refresh adds a time stamp). The installs.ini file stores a hash of the installation path and locks a profile for this specific path to prevent other Firefox installations from using it. The profiles.ini file still stores all registered profiles and their paths and can include the data stored in installs.ini. *https://support.mozilla.org/en-US/kb/dedicated-profiles-firefox-installation *https://blog.mozilla.org/2019/01/14/moving-to-a-profile-per-install-architecture/