update
after installing a complete update of Firefox all my saved pages, add ons and history are gone. How do i fix that?
ప్రత్యుత్తరాలన్నీ (1)
All the data you mentioned is stored in profiles. First, read what they are and how to find them: Profiles - Where Firefox stores your bookmarks, passwords and other user data
Another profile may have been created as a fail-safe (restoration attempt) due to a problem with the update but the old one should have stayed saved, just not used by default. Type about:profiles into your address bar to enter the Profiles page and see if the older one remains. Open it in another window. If it's the correct one, set it as default. If Firefox has trouble opening the profile (likely due to add-on conflicts or corrupted files), try to run it in Safe Mode or copy important data to your new profile. Read the following articles to learn what I'm talking about and how to do it: Profile Manager - Create, remove or switch Firefox profiles Recover important data from an old profile Back up and restore information in Firefox profiles
Reply if you run into issues or need more help.