If you checked those options it will clear out regardless since that is a new Windows it consider that and clears out everything. And what do you mean used to work? How did you document that?

If you use "Clear history when Firefox closes" to clear the browsing history then you can't restore tabs from the previous session because clearing history this way overrides sessionstore. You will at least have to disable clearing the history. You can always clear history manually yourself, but you can't do this automatically when you close Firefox if you want to use sessionstore to reopen tabs.

Give this a try; Expire history by days Allows to expire history older than a fixed amount of days.

WestEnd said

And what do you mean used to work? How did you document that?

cor-el said

If you use "Clear history when Firefox closes" to clear the browsing history then you can't restore tabs from the previous session because clearing history this way overrides sessionstore.

It simply worked, until v63-65 I think. I'm using FF since version ~1.5 by the way. To me, it is a bug as "places.sqlite" and sessionstore/"recovery.js" are different files and have completely different functions ! Plus the fact that the "Restore previous session" checkmark keeps checked BUT the session does not get restored, is really confusing to users, don't you think ?! If there's no bug filed in bugzilla, I need to create one. It's not the only bug I've seen in the GUI, or rather non matching values between checkmarks in the GUI and values in about:config. And that bothers me a lot as I'm using a mozilla.cfg file to set preferences.

You will at least have to disable clearing the history. You can always clear history manually yourself, but you can't do this automatically when you close Firefox if you want to use sessionstore to reopen tabs.

Yeah, I realized unchecking "Delete history and downloads" would work ... As said above, how counter-intuitive. In fact, and fortunately, I only have a few "always fresh" profiles, most of them keep history and session. In my mozilla.cfg file I used defaultPref("privacy.clearOnShutdown.history", false); instead of lockPref(...).

And thanks for the addon suggestion, but I use zillion of profiles so addons are a no-go ;)