When I started Firefox this morning, it acted like there was a fresh install; all default settings were missing like default home page, etc. BUT - "about" still shows v75.0. Then, found out that my login info and Ebay history no longer worked. Saw that "logins.json" and "handlers.json" were both renamed to "logins.json.corrupt" and "handlers.json.corrupt" respectively. There was a "new" "handlers.json" apparently created. I copied the "logins.json.corrupt" file to a new "logins.json" file, and it appears that my logins are back. At the same time, my Norton complained about an error "3038, 105", and did a self-repair - now is "happy". Question: is there some incompatibility between FF 75.0 and Norton? I never had any issues before the last upgrade to 75.0 - now, twice lost these json files. The last time, I had to completely re-install FF to get back a working browser.