One possible reason for this is an instruction in a user.js file. Firefox checks for a user.js file at startup, and it will override your own preferences. This article describes how to check for this possible problem: How to fix preferences that won't save.

Note: If Windows hides .js and other file extensions, you can turn on the display of file extensions (so you can work with files more accurately) using the steps in this article: http://support.microsoft.com/kb/865219.

If you find a file and want to check the file contents, you'll need to open it in a text editor (don't double-click) and look for "browser.sessionstore.resume_session_once" set to true.

A second possible reason is if Firefox is not shutting down cleanly, and is always recovering from a perceived crash. To see whether this is the issue, you can change what Firefox does after a crash so that instead of automatically showing previous session tabs, it shows you a list of tabs. Here's how:

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

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

(C) Double-click the browser.sessionstore.max_resumed_crashes preference and enter 0 (that's a zero) and click OK.

The next time Firefox starts if you get the screen saying "this is embarrassing" and showing a list of your last session tabs, then the problem is that Firefox is crashing during shutdown.

Does any of that help with your startups?

You can check if you have an user.js file in the Firefox profile folder that sets the browser.sessionstore.resume_session_once pref to true.

• http://kb.mozillazine.org/browser.sessionstore.resume_session_once

Jscher

Thanks for the response. It appears I do not have a user.js file. I have hidden files turned off. I had made some setting changes to the about:config, but not the max session restore. I changed that to a zero and that didn't fix the problem.

Any other ideas?

George

cor-el

I cannot ind any user.js file.

Thanks

George

Hi geotanty, what are your non-default settings for browser.sessionstore... preferences? You can right-click > Copy them for pasting into a reply.

jscher

They are:

browser.sessionstore.debug;false browser.sessionstore.interval;15000 browser.sessionstore.max_resumed_crashes;0 browser.sessionstore.max_tabs_undo;0 browser.sessionstore.max_windows_undo;0 browser.sessionstore.postdata;0 browser.sessionstore.privacy_level;0 browser.sessionstore.privacy_level_deferred;1 browser.sessionstore.restore_hidden_tabs;false browser.sessionstore.restore_on_demand;false browser.sessionstore.restore_pinned_tabs_on_demand;false browser.sessionstore.resume_from_crash;false browser.sessionstore.resume_session_once;false browser.sessionstore.upgradeBackup.latestBuildID;20131205075310

Thanks

George

These are definitely different from the default values and may make it impossible to re-open a closed tab or window if you ever wanted to:

browser.sessionstore.max_tabs_undo;0 
browser.sessionstore.max_windows_undo;0

However, nothing there seems that it would override how Firefox normally starts up.

Do you have any extensions? I don't know which extensions would affect the way Firefox starts up, but perhaps you could review your list on the Add-ons page. Either:

• Ctrl+Shift+a
• orange Firefox button (or Tools menu) > Add-ons

In the left column, click Extensions.

Do you see this line in the prefs.js file in the Firefox profile folder after you have closed Firefox?

user_set("browser.sessionstore.resume_session_once", true );

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

• Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder)

Ad Blocker Forecast Fox IE View Ad Blocker Norton Identity Safe Norton Vulnerability

But nothing new or updated lately and this problem just started a few days ago. Would doing a reset help? I was reluctant to do that, but would if it would solve this.

Thanks

George

Hi geotanty, it's odd that you have two different ad blockers. The best known is Adblock Plus. Is that one of them?

A Reset could be helpful, but to check that, you might create a blank profile as a test. It will have even less information than a Reset profile. In case the bad behavior only occurs after restarting Windows, I'm not sure when it would be safe to conclude that a new profile (or a Reset) has solved the problem.

Create a new Firefox profile

A new profile will have your system-installed plugins (e.g., Flash) and extensions (e.g., security suite toolbars), but no themes, other extensions, or other customizations. It also should have completely fresh settings databases and a fresh cache folder.

Exit Firefox and start up in the Profile Manager using Start > search box (or Run):

firefox.exe -P

Any time you want to switch profiles, exit Firefox and return to this dialog.

You'll click the Create Profile button. I recommend using the default location suggested, and to avoid data loss, not re-using any existing folder. Then start Firefox in the new profile you created.

Shockingly blank, I know, but hopefully sufficient for a test.

When returning to the Profile Manager, you might be tempted to use the Delete Profile button. But... it's a bit too easy to accidentally delete your "real" profile, so I recommend resisting the temptation. If you do want to clean up later, I suggest making a backup of all your profiles first in case something were to go wrong.

jscher

I had searched for a file called user.js and it said I didn't have one. Cor-el showed me how to open my profile folder and I saw a file just called USER. I opened that and it shows

user_pref("extensions.autoDisableScopes", 0); user_pref("extensions.shownSelectionUI", true); user_pref("browser.sessionstore.resume_session_once", true);

Should I change the last line, last word to false?

Thanks

George

jscher

Ad blocker blocks ads, flastblock stops windows running commercials that use Flash. At least that what I thought.

George

Cor-el, see my response to jscher above. Once I found a user file, there was a line pertaining to this. But wanted to confirm with one of you that I should edit that last line to false before doing so.

Thanks

George

You can remove the user.js file as it shouldn't be there and prefs created this way can't be modified permanently, but only for the current sessions.
The extensions.autoDisableScopes = 0 line will make it possible to override a block to install extensions in other locations, so with this line present other software can silently install extensions.

You should reset this pref on the about:config page after having removed the user.js file.

extensions.autoDisableScopes

jscher and cor-el

Removing the user.js file solved the problem

Thank you very much, both of you for soling a minor but vexing problem

Enjoy your day.

Regards,

George