Use profile manager to create an additional profile see managing profiles

If multiple versions of firefox are used, for instance a stable firefox 3.6.15, and a firefox 4 beta, you are recommended to create an additional profile (the profile stores firefox user data) so that a separate profile may be used with each version.

I do not think Firefox instructions make this clear, but failure to heed such advise will result in problems. It probably also helps to create a new start icon with -P appended so that the beta version always starts in a correct profile.

See http://kb.mozillazine.org/Testing_pre-release_versions for details

If you have continuing problems, other possible causes are discussed in firefox hangs.

I hope this works for you, if so please mark the post as solved, using the button, otherwise post back and ask for further ideas.

This was no help sorry. I only have one version of Firefox on my computer and I actually uninstalled it and then went to the website and installed it again. It is still freezing everytime I use it. I do believe that it is a problem with the newest firefox. Thanks

I believe over a million users installed the new versions. Serious problems like the ones you have should have been picked up and corrected long ago. All I can suggest is that you look at firefox hangs and firefox crashes.

Problems today when 3.6.16 installed. First, Norton 360 flagged a security risk in an exe file (plugin-container.exe). Then Firefox hung. Restarted Firefox, and after 10 seconds it crashed, and continued to crash on restarting. I had to carry out a restore back to 3.6.15, no problems now.

I wonder if the problem is with Norton 360 ? If Norton 360 is blocking Firefox, or installation of Firefox components possibly a firefox hang or crash may be expected.

I recall a recent thread about Norton and firefox plugin-container.exe, but in that instance my Norton Internet Security was merely giving low grade warnings about new software, rather than specific security problems.

Some related threads where Norton possibly is finding false problems

• https://support.mozilla.com/en-US/questions/789227 " After installing 3.6.15, my Norton 360 says that plugin-container is unknown ... "
• https://support.mozilla.com/en-US/questions/789274 "Firefox fake update

add-on is a virus? "

• https://support.mozilla.com/en-US/questions/789442 "How do I go back to firefox 3.6.14? 3.6.15 crashes when I open."

Same problem here. Updated to 3.6.16 today. Now Firefox hangs up every time I launch it. Didn't have problems until this newest update.

@sleepysyrup
Sorry to hear you have problems.

I am having no problem on Windows XP with Firefox 3.6.15 , 3.6.16 or with Firefox4.0 , obviously Firefox works for some of us and more information may help in tracking down any problem.

If you are having problems with Norton & firefox it may help to see the exact text or a screenshot of any warnings.

If you have problems with Firefox hanging but not due to Norton, you may do better to start your own question, including as much information as possible, and reading firefox hangs

My problem isn't related to Norton. I'm dealing with the problem as originally posted by quinyb.

I went ahead and installed 4.0, but I'm having the same problem with it that I had when I updated to 3.6.16. No error messages, just hangs.

I think I've narrowed it down to a problem with the plugin-container.exe, which is not showing up in Windows Task Manager. Should it be starting up when Firefox is launched?As long as I'm on a page with no plug-ins, I'm okay. If I try to load a page with Flash or some other plug-in, that's when it hangs up.

So I've been having this problem for the past couple days, after I installed the 4.0 Beta 12, but not immediately. I resorted to using IE8 until I could troubleshoot. Today I uninstalled and reinstalled, initially keeping my customizations, then again without. Upon installing the new RC I imemdiately had the same problem. For me what goes wrong is Firefox will open correctly and begin to load a page or pages, and about 15 seconds in, usually after all loading is done, it will seemingly freeze, or hang rather. Seemingly completely unresponsive.

Here is the aha moment: I became fed up with this and was just trying to get to the troubleshooter's containing file or whatever, [so that I could delete the session restore javascripts, like the support page says to try for hangs]. It hang right before I was able to open the containing folder. Instead of trying to fix it or wait I immediately alt-f4ed it. But firefox remained, and to my surprise, it worked completely fine. Normally, when its hanging, any click on the window will just make a windows BING sound and be compeltely unresponsive. After attempted to close firefox, it actually worked fine.

This leads me to believe there is some masking window that makes firefox appear to be hanging, but in reality its working totally fine.

I've attempted to unmask this by dregding through process explorer, but so far to no avail. I'm no expert, but I figured if this board hasn't realized this yet someone can figure it out from here far better than I can.

Let me know when you figure it out to so I stop using IE. Even though Firefox functions after I alt-f4 the "mask", I don't know if the 'mask' is harming my system or giving me malware or what so I'd rather not fuck with it.

@emnacstac,
If you have been using beta and RC versions of Firefox, you may well have multiple versions of firefox installed. If you use more than one version of firefox you should have a separate and unique profile for each version, as explained in my original reply in this thread.

If you start switching back and forwards between versions of firefox and do not have separate profiles you may well run into problems.

There may not be any need to worry about some mysterious masking window / process. Firefox will lock certain profile files when in use, and will need to modify some of the profile files, problems may arise when two versions fight over the same profile, or if firefox did not close down in an orderly manner.

@john99 I uninstalled all versions of Firefox. The problem did begin while I had two versions installed, but I have since uninstalled both and reinstalled only the new RC and the problem has continued. I don't know what this means.

@Emnacstac.

Thank you!. I had exactly the same problem, and thanks to you have now tracked it down and resolved it ... at least in my case. For me, it was caused by an add-on called 'Conduit Engine 3.3.3.2'. When FF 4 Beta 12 freezes, press Alt-F4 to 'free it up' so you can get to the menu. Then go to 'Tools, Add-ons', and disable 'Conduit Engine 3.3.3.2'.

Then restart FF.

I've played around, and it consistently seems to be that add-on that's freezing FF for me. As you say, it seems more like an invisible process that prevents FF from being able to get focus in Windows.

Thanks again.

John.

see above

If anyone has continuing problems it may be best to start your own question, that has the advantage that anyone answering it is answering only one question, and should have your System Information available.

It may be worth reading the questions and anwers in this thread, especially the links shown in light blue to the Knowledge Base articles

I am running firefox 3.6.16 under W7 I usually have only one instance of firefox running at a time. Since I applied 3.6.16 firefox starts ok but immediately freezes - all buttons, menus, corner icons etc are dead. If I do alt+F4, all is ok again and stays ok for the rest of the firefox session. If I restart firefox, I have to alt+F4 again. This is a slight nuisance but in no way disabling. Cheers

I have the same problem. I'm using WinXP SP2. After installing FF4 it freezes when I open it, but when I open a second firefox browser, the second one works just fine, but the frozen one has to be opened up at the same time, and I cannot close the frozen browser without task manager. Reverted back to FF 3.6.1.6 and now it has the same problem! - I remember that I got an error message about plugin-container.exe a few days ago (it had to be shut down), so maybe it's related to the problem?

I tried the ALT-F4 and it just asked me to close the program. I have window vista. I have uninstalled the only version of FF I have and still have this problem. Ihave actually done this twice. I have simply give up and am using IE again...uggggg!

Search for:

places.sqlite (history stuff+favicons etc etc)

urlclassifier3.sqlite (google phishing url's, will be rebuild)

Must be somewhere in your profile directory...DELETE them.

@martijn2011

I am not sure such actions are always going to be for the best. Creating and using a fresh new profile may be a better idea as a test, and a safer procedure. Creating a fresh profile can solve many problms relativly safely, that is much more of a one size fits all solution.

• see BasicTroubleShooting-newprofile

CARE You may loose important data if you delete files

Deleting profile files
places.sqlite is important, as it is your bookmarks and history, any rebuilding will be dpendent on the backups being ok. IF you consider deleting it you should either rename it eg to places.sqlit.old1, or better still rename it and move it, such actions give you a chance to restore it should there be a problem. Whilst the profile manager is still available, using that to create a fresh profile is probably the easiest and safest way of tackling some problems.

• see profiles for inormation on how to find the profiles folder, what it contains and what you can do with it.

Cache Path
On my system and iirc since at least version 2 of firefox the cache files are in a separate path from the (default location of ) main profiles. urlclassifier3.sqlite will be a cache file. the easiest method of finding such files, and information about them is to type into the location bar about:cache

I am not certain this sort of problem is going to be helped by deleting urlclassifier.

places.sqlite should be rebuild by your bookmark.html or the json files in the bookmark folder. But ofc its better to rename it for awhile first.

About the urlclassifier3.sqlite file, the same, rename it instead of delete, and see what happens: http://ychittaranjan.wordpress.com/2008/06/27/urlclassifier3sqlite-woes-on-firefox-3/

A more generetic approach is to check your profile folder for files above 10Mb, search for info and try to rename them. This is what i did, and the constant freezing for 2 sec every 10 seconds is gone.