Note that the current release no longer uses sessionstore.bak but uses the sessionstore-backups folder instead.

previous.js (cleanBackup: copy of sessionstore.js from previous session that was loaded successfully)
recovery.js (latest version of the sessionstore written during runtime)
recovery.bak (previous version of the sessionstore written during runtime)
upgrade.js-<build_id> (backup created during an upgrade of Firefox)

The sessionstore.js file in the profile folder is still used to store session data, but is only present when Firefox is closed.

The sessionstore.js file is created from recovery.js when you close Firefox and is removed and copied to previous.js when you start Firefox.

You can copy a file from the sessionstore-backups folder to the main profile and rename the file to sessionstore.js to replace the current file (make a backup copy of the current sessionstore.js).

If you wait (too) long to update then it is possible that some files are not fully compatible the the current release and you can experience issues.

Are you restoring all tabs on startup?

• Tools > Options > General > Startup: "Don't load tabs until selected"

The "Don't load tabs until selected" setting toggles the browser.sessionstore.restore_on_demand pref on the about:config page. There is a browser.sessionstore.restore_pinned_tabs_on_demand pref for pinned tabs that isn't affected by the setting in Options/Preferences.

browser.sessionstore.restore_on_demand
browser.sessionstore.restore_pinned_tabs_on_demand

You can open the about:config page via the location/address bar. You can accept the warning and click "I'll be careful" to continue.

• http://kb.mozillazine.org/about:config

I wonder why you felt you needed to vclog this thread up with soooooo much unnecessary information?

Have you looked into more effective tab management rather than just leaving nearly 2k tabs oppen at all times?

Tabs are being loaded only when i click on them

and if by unnecessary info you mean PC specs that is just copy paste from a .txt file that i keep in need of troubleshooting in games and other app's

from my experience in games, os , and app's problem resolving more info the better

and i already explained everything about how tabs are being opened and loading times on the very beginning in my first post

and when i try to install new version of FF i first uninstall v28 and delete both of these folders

c:\Users\USER\AppData\Local\Mozilla\ c:\Users\USER\AppData\Roaming\Mozilla\

and than i install new version with just tab mix plus and i copy sessionstore.js in c:\Users\USER\AppData\Roaming\Mozilla\Firefox\Profiles\4j0mi1a7.USER\

i just did a test with 1777 tabs

FF 28 with 18 active add ons themes etc....

1 minute 11 seconds before i can start working

FF 40b9 only one add on tab mix plus

3 minutes before i can start working

maybe if you can give me a link to 64bit install only for FF 39 or 40 because i goggled and searched everywhere and i can't find 64bit FF

Are all those tabs normal tabs (not pinned) and are you restoring all those tabs?

What is the size of the sessionstore.js file?

The sessionstore.js file is only present in the Firefox profile folder when Firefox is closed.

You can use this button to go to the current Firefox profile folder:

• Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder)
• http://kb.mozillazine.org/Profile_folder_-_Firefox

If those tabs have a large back/forward history then this can add to the size of the sessionstore.js file and the processing of the file on startup.

size of sessionstore.js is 3 mb

tabs are not pined nor private just normal tabs

yes tabs are restored every time i start ff

i did follow this manual

Note that the current release no longer uses sessionstore.bak but uses the sessionstore-backups folder instead.

previous.js (cleanBackup: copy of sessionstore.js from previous session that was loaded successfully) recovery.js (latest version of the sessionstore written during runtime) recovery.bak (previous version of the sessionstore written during runtime) upgrade.js-<build_id> (backup created during an upgrade of Firefox)

The sessionstore.js file in the profile folder is still used to store session data, but is only present when Firefox is closed.

The sessionstore.js file is created from recovery.js when you close Firefox and is removed and copied to previous.js when you start Firefox.

You can copy a file from the sessionstore-backups folder to the main profile and rename the file to sessionstore.js to replace the current file (make a backup copy of the current sessionstore.js).

and it worked BUT as i said to slow 3+ minutes

Do you really have to restore all those tabs on a (re)start?

If you chose not to restore all those tabs then you can shorten the startup time considerately.

• Tools > Options > General > Startup: "Don't load tabs until selected"

when i start FF i can see all the tabs and the are greyed out and are being loaded only when i click on them

here http://i.imgur.com/kuGte7G.jpg

Something you've ignored multiple times is, Why are you trying to load almost 2k tabs? Firefox has multiples tab management solutions, either built in (Bookmarks, Tab Groups, etc.) or via add-ons that would make this much better. The browser isn't used to start up with that many tabs very often, so it's not odd that it's slow

Tyler Downer said

Something you've ignored multiple times is, Why are you trying to load almost 2k tabs? Firefox has multiples tab management solutions, either built in (Bookmarks, Tab Groups, etc.) or via add-ons that would make this much better. The browser isn't used to start up with that many tabs very often, so it's not odd that it's slow

this is the only tab management that suits me the best i tried other solutions

tabs are not being loaded till i click on them

and FF 28 is not so slow but any version after 28 is as you can see in posts above

ok thanks for "help" ill stay on 28 for a year or two more maybe by that time any future version of FF will be faster than 28

Keep in mind that Firefox 28.0 is getting increasingly more vulnerable as it does not have any of the security patches since, many of which were critical. https://www.mozilla.org/en-US/security/known-vulnerabilities/firefox/

i don't have a choice

Why do you need to have so many tabs? You could bookmark those pages and open them only when you need them. That is what bookmarks are for - storing pages.