Firefox traditionally has stored your current session windows and tabs in a file named sessionstore.js and when you exit and start a new session, it renames that file to sessionstore.bak and starts a new sessionstore.js. The older sessionstore.bak gets deleted at that point. I'm not sure how you were able to access earlier history that Firefox had deleted. Is it possible you had an extension like Session Manager or Tab Mix Plus that can store additional session history files???

Incidentally, within your session, there may be closed windows and tabs available from the History menu.

On the classic menu bar, there are two sub-menus: History > Recently Closed Tabs and History > Recently Closed Windows.

On the new 3-bar button menu, when you click History, the closed tabs and windows are listed there above the more general list of history.

being as how some of tabs in question were weeks or months old, thats not much of an option, Also I have been taking advantage of several 'layers' of restore for a long time (year +) and I keep a low count of addons and I have seen this on both my PC And my Mac... the closed tabs and windows are grayed out and have been for months - no 'direct' connection to this

Thx, I will have to look into Session Manager or Tab Mix Plus, see if they will do this. FF has already been p###ng me off with removal of the old (and separate) download window replacing it with the new 'library' style download/history window making it a real pain in th a$$ to retry failed dowloads = switching back and forth functions instead of having them side by side and just looking at whats missing and copying it over. that, and this constant trend of stripping capabilities have me ready to salvage my profile folder and drop to and stay with FF 24 before this idiocy started

ps I do have the download win. addon - its 'ok'

sorry to vent, I REALLY hope people at mozilla read these.

Not sure if these two problems are related but I've been having problems with reopening tabs and not having them load properly (see https://bugzilla.mozilla.org/show_bug.cgi?id=1004369).

What's annoying is that if FF crashes and about:sessionrestore comes up it shows a blank white page. sessionstore.js still has all my tabs contained within it BUT trying to manually open about:sessionrestore by typing it into the location bar and pressing enter clears sessionstore.js (though sessionstore.bak remains untouched).

Copying and renaming sessionstore.bak to sessionstore.js doesn't work either; FF clears the resulting sessionstore.js as well.

PS

I use both Session Manager and Tab Mix Plus but Session Manager doesn't really seem to work when trying to use a saved session as a startup session since the update to FF29, but Tab Mix Plus seems to work. The difference between the two is that Tab Mix Plus forces every tab to load at startup whereas Session Manager only loads the first tab that opens at startup.

Update; I installed Session Manager, although it seems to work fine it is Nothing like the situation I described earlier; having the 'this is embarassing' 'restore session' window after a crash or force quit, ie; list of all tabs from last session, then in that list is a 'restore session' link or several, - I may have a copied sessionstore file in my backups if I can find it.

I did not have Tab Mix Plus or Session Manager at the time, although Session Manager works, I would like to have the option the old method

Hi Nighthawk.rl, Firefox normally only displays the previous session window and tab list when resuming from a crash, after at least one failed attempt to simply load them all. If you used to see that more routinely, maybe Firefox was crashing all the time back then?

If you prefer to bypass Firefox's attempted automatic restore so you get the list every time, there is a setting for that. I don't know how this works with the Session Manager extension, however...

(1) In a new tab, type or paste about:config in the address bar and press Enter. Click the button promising to be careful.

(2) In the search box above the list, type or paste sess and pause while the list is filtered

(3) Double-click the browser.sessionstore.max_resumed_crashes preference and change the value from 1 to 0 and OK that.

Yes, FF did crash frequently back the (And still does almost daily - often overnite when nothings going on) also crash reporter has a "problem submitting report" every time

Ill give to other ideas a try ... meanwhile I have an engine to replace... what would I rather do?.....