Firefox automatically saves closed sessions when Firefox is closed properly. If you are using the default Homepage - about:home - the previous session can be easily restored using the Restore Previous Session button in the lower-right corner of that page. And if you are using a different Homepage you can open History and use the Restore Previous Session menu item. There is no need to "kill" the Firefox process and trigger the "crash restoration" feature in Firefox.

Comparing one method of restoring just one (the most recent) previous session to another is useful in its own right, I suppose - but it cannot be used to address my core issue. . But first I'd like to mention that if all my tabs are in a single browser window, then just hitting the "X" in the upper right corner seems to do exactly what killing the task in task manager does. Or alt-F4 does, for that matter. . Completely unrelated, some may find it interesting to note that ctl-F4 is a great way of closing tabs in reverse order to their creation. . Anyway, I am still left with the problem of having currently eleven different "*Restore Session.xht" files that I would like to selectively restore, but cannot because of a single xml parsing error. It would be nice if the system would identify the error, instead of just listing the line and column where it occurs. I don't have an easy way of identifying where in the .xht file it's pointing to. Not being the slightest bit interested in learning xml or learning and installing an xml editor that this information would make sense to. But maybe I'll have to become rudimentally aware, but only as a last resort. I just hope there's some xml expert who knows (or can guess) why such an error occurs and how to fix it (by notepad editing the .xml file). . It does strike me that locating the "sessionstore.js" file (in Windows 7, usually in "C:\Users\Administrator\AppData\Roaming\Mozilla\Firefox\Profiles" if logged in as 'Administrator') and making a unique copy upon exiting FireFox (by whatever means) could be the solution to my problem, I'll let you know after some testing ... . pcG

Where do you find the Restore Session.xht files? I'm only aware of the sessionstore.js and sessionstore.bak files.

Maybe you would be interested in something like the Session Manager extension: https://addons.mozilla.org/firefox/addon/session-manager/

Although there isn't a native feature to save session per-windows, you can right-click any tab in that window and bookmark all tabs. State data is not maintained, but at least the URLs are saved.

This sounds like something added by an extension that may have been disabled for some reason.

Are there any disabled extensions listed here: Firefox/Tools > Add-ons > Extensions

Note that your System Details List shows that you have a user.js file in the profile folder to initialize some prefs on each start of Firefox.

The user.js file is only present if you or other software has created it, so normally it wouldn't be there.
You may want to check its content with a plain text editor if you didn't create this file yourself.

The user.js file is read each time you start Firefox and initializes preferences to the value specified in this file, so involved preferences can only be changed temporarily for the current session.

See also:

• http://kb.mozillazine.org/Preferences_not_saved

[next up - replies to above questions - but this comes first]...Well, it appears that making periodic copies of 'sessionrestore.js' (i.e. 'copy [...use.your.correct.path.here...]\sessionrestore.js c:\20130817-20.01-sessionrestore.js' [for saving the 8:01pm August 17th 2013 version of sessionrestore.js]) works just fine. In fact, one could write a program that grabs the current date and time and add it to the beginning of the filename being copied (saved) as it seems that 'sessionrestore.js' is continually being updated and exiting FireFox at all is completely superfluous and unnecessary - copy the .js file while all your tabs are still open).....now idle curiosity begs me to ask why this place rejects the CR/LF that the rest of the universe has adopted some forty years ago...right...I have already questioned the sanity of those inhabiting the inner sanctums of the Mozilla universe and this is just corroboration.pcG.

[jscher2000].'Restore Session' is what the 'oops ...' page (with all the checkmarked browser windows and included tabs) is called by default [the single tab also has the label 'Restore Session'], 'Restore Session.xht' is what it's called when you choose 'file - save page as' [ctl-s] {late note, just went to my XP machine to double check this - and it defaults to wanting to save 'Restore Session.xhtml'}. As far as I'm concerned, if the Mozilla folks create this web page (originally to apologize and recover from their many early crashes), then it's a bug that it fails to behave as a properly saved web page. The 'XML parsing error' that appears when trying to load a saved page created by them is uncalled for. It should work and they should fix it soonest. I plan to hold my breath while waiting on this any day now...---Mozilla is going to have to adopt "we will move heaven and earth to make sure the add-ons that worked before the update still work after the update" before I'll waste my time adding anything like session manager.---+++The right-click saving all tabs (just in the current window, I presume) is something I'll look into, thank you+++ pcG

[cor-el].Not that I can see. Mozilla is so horrible at Add-ons/Extenstions/Plugins/whateverTHEYdidn'tCREATE, that I avoid these areas as it tends to give me a headache and forces me to rush to "FireFox made me sad" way too often.---user.js was indeed added by me - forget the entry (but user.js overrides the system default - forget the name). The theory as I recall is that after setting your home page, you make user.js read-only and no program has successfully changed my home page since [really cool that it works perfectly as advertised - FireFox made me happy on this rare occasion].---+++I've changed preferences and have had no trouble (recently had to revert to 'only load tab when selected' as this current issue that brought me here was due mainly to my having around a hundred or more tabs open in a window and 'load all tabs automatically' was crashing FireFox before they all reloaded. Yes, confessing that porn did this to me. Wanted to save a 'spanking' Restore Session, a 'bondage' Restore Session, a .. well, there are hundreds of categories and except for the Xml Parsing Error, I could have cut things down to twenty or thirty tabs at a time. Still haven't fully checked if my saving different sessionrestor.js files can be managed the way I want [save a master .js with all categories, then close tabs for all but one category and save a .js for that category, then reload the master .js and close all tabs but those for a different category]. Should work, but being enthralled by content and task switching my brain for firefox housekeeping is still a brain stretcher ... which head to think with, big or little or big or little ...~~~.I do thank you (three so far?) for all attempts to help, successful or not.///.You knowing about my user.js feels a lot like I've accidentally posted my diary online ... just a little bit. Thank heaven I don't keep a diary ... pcg

The about:sessionrestore page is an XUL page and not a normal HTML/XML page, so you can't save this page and reopen it.

• right-click on a web page to open the context menu and select View Page Source

This page is loaded via a script that processes the sessionstore.js (.bak) file.

• chrome://browser/content/aboutSessionRestore.js

The only way to open the current copy of this page when starting Firefox would be to use the -chrome command line switch.

• https://developer.mozilla.org/en/Command_Line_Options

Not quite sure what you're saying / implying here. They made the dang browser, so you might be saying they chose a file format that they know wouldn't work so nobody could use it. That would be sick. You might be saying that XUL is incompatible with XML, but that sounds too stupid to be true......Somehow they created a file that works with their browser, so why wouldn't it save correctly? If it can create and display an XUL (?) page, what magical thing happens that it cannot be saved? I have this pet sociological theory that everyone is either evil or incompetent - it would appear that Mozilla is trying to corner the market on both.-----------.that aside, I still think they could fix the error (give XUL as a filetype to save?) and people could rejoice at the plethora of additional functionality ... and why wouldn't they want that? Using a script to gather data from a known source to accomplish a known task cannot be that hard to make work right. Of course, some people just live ... I worked for Epyx they were developing the "handy" (now Atari Lynx). The hardware guy said "nobody needs sound for a game, so I'll be damned if I'm gonna put any effort into it". Humans have this propensity to peel off the "stupid" label, slap on a "smart" label and think they've increased their IQ = like pushing the hands of a clock to invent time travel.[[[[[[[summation:they could fix this, they won't fix this, I will continue to marvel at their ability to see anything with their heads so far up a dark and smelly tunnel.I think I've worked this subject to its conclusion without someone from Mozilla checking in to report they're working on the problem. I have my workaround, and this forum has been invaluable for leading me to it..pcG

Hi pcGnome, the storage format for session data is sessionstore.js. The about:sessionrestore template is used to displaying the data during crash recovery if the previous automatic session restore led to a second crash (I assume you turned off the automatic first restore). I doubt anyone anticipated that you would intentionally crash the browser to display it with the idea of saving it, since by design its appearance should be rare and its mission is to let you deselect problem tabs and windows so you can be more successful restoring your session the second time.

I'm sure many users would like a convenient way to save or export a list of current or previous session windows and tabs. (Preferably without having to change settings in about:config and crash the browser to get it.) You could file a request for enhancement if you want to make the case to the developers that this should be a built-in feature rather than a task for an add-on: https://bugzilla.mozilla.org/.

See also:

• http://forums.mozillazine.org/viewtopic.php?f=38&p=12098147&start=60#p12098147

[jscher2000].Sorry this took so long (firefox stopped updating sessionstore.js, yada yada, reinstalled from scratch, got sidetracked...). . Anyway, things crashed a lot at first, and the idea that I'd want to save the created XUL file is just common sense - if you uncheck a couple of tabs to fix the problem and it doesn't work - you'd naturally have saved it, so you could load it and try eliminating a couple different tabs. My bottom line is - if they create a page to be useful, the greatest usefulness is BEING ABLE TO SAVE IT. To not automatically do so ... well, I still say the folks at Mozilla are really kinda nuts. Take their ad boasting that they are not like the other guys, they care about the user. Nuts. A user would like to disable pop-unders, a user would not want their web browser to report to the new site where I'd just come from. The whole framework for ALL browsers is to serve up the individual to a web site on a platter.....Not going to lobby anyone too blindered to see something this obvious as I've got more useful things to do (like reclaiming a zillion links from saved XUL files that don't work)...The biggest help is, of course, your pointing out the 'save all tabs' option - putting a whole lot of bookmarks (now approaching the thousands), but it's all there. Decided to use macros in OpenOffice to reclaim the web sites in the XUL saved files that don't work - so thought I'd check back in here.pcG

[cor-el].Initial perusal of your link seems interesting, but as I've mentioned - not currently interested in tackling this from a programming side. May be useful in the future (can't have too much technical information, so I thank you for this anyway).pcG

The bad news is that you can't save data that is displayed on an XUL page.
This is the same as with the about:config page that displays content in a similar way (i.e. uses a script to create the page) and also can't be printed.
The only way too reach that content and to be able to save it is by using other methods to parse the content of the sessionstore.js file like posted in the above linked mozillaZine forum page.

That is how it works and you need to accept that such pages aren't real pages in the way that you can see their content in the page source.
The only way to save such a page would be via a screen print (screenshot).

[cor-el] So, sorry to be so absent, but went off on six different tangents. ====== Nevertheless, "because they chose to do it stupidly with complete lack of foresight, so get used to it" just isn't a satisfying answer somehow.
.
I would put it to you that every line (web page) that shows up during "oops ..." also exists as a history element. Which raises an issue in depth with the problem I'm having - STUFF SHOULD JUST FFFKNG WORK! ... Ahem, not yelling at you, but it's an oath I swear to dozens of times every day and the taste of it is very dark in my mouth.+++++++++ So, History, bookmarks, all that stuff should exist in just a regular folder and be a file of probably "text" type. The insistance on making things inaccessible ... well, there's something wrong with the corporate mind. Guess why the keypad on your calulator and your phone are ... WRONG ... One could apply logic and say things like "the zero on the phone is really 10", but that's not it. The idiots at Bell labs made the idiocy seem rational because if they looked the same, people might get confused. Actually, my father being an accountant was pissed off his whole life (gone some years now) over this. If they made the phone keypad the same as the calculator keypad, no one would have to think "which one am I using" before trying to 'touch type' (it's called ten key adder something or other).
.
If you can keep the info intact to write a sessionrestore.js file, you can coordinate THE WHOLE SYSTEM. Every bit of text (like properties does NOT) should be markable and copyable. Every system of keeping track of things should be in the form most conducive to the person using it. Keeping text files in regular folders so I can write the simplest of programs to do very powerful things with MY DATA. And I'm sorry, nobody gets off the hook making my life difficult by claiming they need to protect the idiots (yes, even when it's me) from themselves.....In conclusion, I did solve my problem after a fashion. With an old dos text editor (Brief) I managed to reclaim some thousand URLs from the file that wouldn't work after I saved it. Again, sorry, but if I can recover the data manually, they surely should be able to access it as well.]]]]]]]]] Anyway, my solution was to just grab the whole of my history (starting with July) and just going through them to find the stuff FireFox doesn't give a damm that they tried very hard to lose for me. I did the last minute switch because ... guess what? If I type "show.avi" on the command line, it'll launch a program to handle it. Guess what happens when you issue a "http://domain ..." on the command line? So, yes, I have this long list of URLs that I cannot feed to a browser, nor can I do much of anything with it.
.
These are COMPUTERS, people! In my world that makes them an "anything machine", someone's just got to do it. It starts by reducing virtually everything to a common representation, storage thereof, searching thereof, manipulating thereof, etc ... I did come across an interesting way a thing works with the recycle.bin. If you want to restore just some of the items to completely different places than where you sent them to the bin from, you mark the files you want to "special restore", hit ctl-x, and then select the folder where you want them to go and hit ctl-v (cut, then paste ... how novel!).So, there's gonna be no "it's solved to my satisfaction" here, but recovering thousands of lost URLs by just manually going through the history is about as good as this is going to get. Special thanks for being made aware in this discussion that "save all tabs" and "open all in tabs" were available. Still get a lot of crashes trying to handle hundreds of (this goes here, that goes there and the rest get their current tabs deleted) and as long as I "save all tabs" a lot (and try to keep straight which previous version I can delete because a new one supercedes it). Good thing I don't have a life or anything, right? So, I'll wait a bit to see if we're really letting this all die down ... or maybe just can't let go.... thx much all (few?)
pcG