Firefox v68.x hanging on start. Cannot end task via task manager.

As of Jul 11, I cannot get Firefox web browser to start. The window opens to a blank, white screen and the busy symbol/mouse cursor is stuck on the drain icon. I’ve uninstalled and reinstalled the program but the error persists. I tried rolling back to a previous Windows 7 update setting and was able to get Firefox to work again but only for one session before the error re-occurred. I posted on the Mozilla forums and found that others were having the same issue. Avast/AVG seems to be the culprit as all those reporting the issue are using an Avast product. I uninstalled Avast on my PC and rebooted and Firefox does run so long as Avast is not on the PC. (It won’t run if I just temporarily disable Avast shields.) Any ideas how to resolve this?

Thanks.

What version of Avast were you running? Free, Pro, IS, Premier?

Could you provide a link to the forum where other users are reporting issues with Avast?

Running FF 68.0 64-bit here and no issues.

I am using Avast Free Anti-Virus

program version: 19.6.2383 (build 19.6.4546.507)

Virus definition version: 190715-4

Link to the Mozilla forum discussion.

https://support.mozilla.org/en-US/questions/1264440#answer-1237768

Hi wizzleteats,
I just tried avast 19.6 with latest firefox but it works.
Do you use any browser extensions of plugin. Can you try to disable one by one and test if firefox is able to start properly ?
Thank you for report !

Unfortunately, I can’t. Firefox hangs as soon as I try to run it so I cannot access any features that will let me disable plugins.

wizzleteats
can you try to disable avast self defense, rename “c:\Program Files\AVAST Software\Avast\aswJsFlt.dll” to “c:\Program Files\AVAST Software\Avast\aswJsFlt.dll.org” and restart firefox. If you cant kill it open task manager select firefox and push end task button.

It won’t let me rename the file. Says I need administrator permission. When I try to grant permissions on the Avast file, it refuses to allow it.

using task manager to end the Firefox.exe process doesn’t work. It just stays there using up ~35,000 kb.

Hi wizzleteats,
did you disable avast self defense ?
Can you download process explorer (https://docs.microsoft.com/en-us/sysinternals/downloads/process-explorer) run it as admin
select firefox.exe process than right click and in context menu click to create a dump → create full dump.
Please upload dump of all firefox processes to avast ftp server for analysis. (https://support.avast.com/en-eu/article/FTP-file-upload)
It will help us find why firefox got stuck !
Thank you

Thanks for helping me with this. I appreciate it. I wasn’t aware that I needed to disable protections. After renaming the .dll file, I’m able to end the Firefox.exe program in the process tree but Firefox still doesn’t work. If I try to start it now, no window opens. I just get an error message saying that an old copy of Firefox is already running and needs to shut down. It then keeps trying and failing to restart firefox and I see several instances of firefox.exe trying to open and then shutting down.

The file was uploaded as firefox_got_stuck_wizzleteats.zip

wizzleteats even when you kill all firefox instances via process explorer and start clear new firefox.exe process It fails to start ?
Please try to disable avast components one by one and test if it helps or not. (Web shield, File Shield, Antirootkit, Behavioral Shield)
Thank you for help !

I cannot kill the final instance of firefox.exe via process explorer. It does not appear in Task Manager but it does show up in Process Explorer but trying to kill the process or the process tree does not get rid of it. Disabling components in Avast one by one doesn’t work.

I’m no expert on Firefox processes (understatement) but have you identified what that FF process actually is?

Currently on my system the three FF.exe processes shown are the main browser, the user settings/preferences (presumably the profile info) and, in my case (with a private window open) a private window.

The process you can’t end looks like, from its size, that it is the main browser .exe but it might not be so if you can identify exactly what it is it might help someone else here identify the problem.

Serious problems with FF, including not shutting down, are sometimes blamed on the user profile corrupting ie. it is trying to load the profile before it shuts down but can’t so gets stuck in a loop. That’s the theory I’ve read - no idea if there is any truth in it.

But it might be worth considering a FF Reset if not already tried. That should return the installation to default factory state and a new profile created. Under the FF Help tab you’ll find the option in Troubleshooting information.

I can’t advise whether this is a sensible thing to try, it could mean a lot of work to get FF to be re-customised back to how it was before and it might not even work. But if I had a FF installation not functioning properly and other saying that there is no problem with up to date AVAST + up to date FF then I’d be looking at it as more likely a FF issue rather than another program provoking it.

Thanks. I’ve already tried reinstalling FF with my profile intact and with a completely fresh install. Neither works.

Hi wizzleteats,
as admin you should be able to kill event system process :-(.
It looks like firefox process got stuck in some kernel mode call can you try to induce it again and make kernel mode dump ?
To create a full memory dump you need to set it up see https://community.sophos.com/kb/en-us/111474 and
here s a tool for it https://docs.microsoft.com/en-us/sysinternals/downloads/notmyfault. Start is as admin and press the crash button.
Please zip the dump as wizzleteats_BSOD_7_2019.zip and upload it to avast ftp server https://support.avast.com/en-eu/article/FTP-file-upload
Thank you for help !

I’m not comfortable making edits to my registry.

You should not have any problems with if you follow the instructions in that first article.

The important thing is to backup the Registry first if you have to edit it. I think it explains it but in simple terms you just type in “regedit” in the Run box and at the top of the window which appears click on the File tab. That will offer you several options, the one you want to use is Export. That simply backs up the Registry to a location of choice. Name the file: Registry Backup with the date.

When you click on Save that’s what it will do. It should take takes 10 -30 secs depending on your system. There’s no progress bar, just the whirly gig cursor to indicate something is happening and you get no confirmation of the backup having been made when it is finished so check you have a .reg file at that location afterwards. It should be several hundred MB in size.

If something goes wrong with your later Registry editing you just reverse the process, instead of Export you use Import and that file will be used to return the Registry to its previous state.

Hi,
we contacted mozilla firefox team to help us resolve this issue but we neither mozilla is able to reproduce it !
https://bugzilla.mozilla.org/show_bug.cgi?id=1567144
We really need a memory dump or a remote session to move at least one step forward.

As I said previously, I’m really not comfortable with making changes to my registry. I’m not really that knowledgeable with the inner workings of the operating system. I appreciate all your efforts to resolve this problem but as it doesn’t seem like a solution is forthcoming, I’ve removed Avast from my PC and switched to Windows Security Essentials. Firefox is once again working with Avast removed from my PC.

Same problem, thanks

Hi,
you dont need necessary modify windows registry, just open run dialog and type sysdm.cpl , choose advanced tab and select complete memory dump. Steps 1…6 described in https://community.sophos.com/kb/en-us/111474 . Only when Complete memory dump is missing you need to work with windows registry.