If you’ve upgraded from an older version of Firefox to version 67 or higher and noticed your bookmarks, add-ons no longer there in Firefox, you’re not alone! This issue is bothering a lot of users right now where Firefox creates a new profile and makes it default, don’t fret! Your old profile is still there and you can switch back to it easily.
First, launch Firefox and type in about:profiles in the Firefox browser URL bar, hit enter:
Next, you’ll notice the newly created profile as default-release. What we want instead is the profile called default. Under the Profile: default select Launch profile in new browser, this step is solely to confirm the profile is the one you are looking for. If for some reason that profile is not your old profile, you may need to attempt this step on another profile in the listings until the old profile is verified.
When the right profile is located, simply click on Set as Default Profile. And you’re done!