After indications from my father that the new Firefox was a disaster for him, no longer working with SessionManager, UnMHT, DownThemAll, etc (and had visual changes that looked more like Firefox 20 than Firefox 56)... since I had not yet updated, I changed the option to "download updates, but let you choose to install them". Yet next time I opened Firefox, it installed the update without asking. I see you have archived/closed bug reports of this for years. Yet it still happens. Blarg. You don't let us revert easily, you install when I told you not to, and you rush out a new version before half of the API calls are in place to help old extensions work. Garbage, absolute garbage. Now I have large collections of useful webpages stuck in Sessions Manager that I cannot get to, and you've caused me (and many other users) extreme frustration. The only reason I used Session Manager is because FF was never 110% reliable on storing past pages, and didn't have advanced methods to managed saved pages. You say you have "telemetry" that makes you confident that "the vast, overwhelming majority of Firefox users" won't be affected by the breaking of many plugins, yet you rushed out the version before you had the APIs to even support half of the producers to update them. Rather than dedicating significant resources to a "refresh your UI to keep things looking modern", and replacing most of the "top sites" new tab window with your money making "recommended by pocket" crap... fix your issues first and foremost. You don't care about the needs of your users, period.