With something of Firefox running in the Task Manager after shutting Firefox down could be a Extension/Addon.

You have not provided any information as to what they maybe or if you are running any. This could be the issue; as well what protection are you using besides a VPN ? Have you scanned with Malwarebytes ? Click the Free Trial Link : https://www.malwarebytes.com/premium/ and please do give self a scan.

You have not added what version Windows 10 you are running, current is version 1903 and fyi if running version 1803 Microsoft is force updating everyone to 1903 so expect to be updated. Can find this from Settings --> System --> About

It is possible Windows has a corrupted file which could be a issue, if so you can correct that with this information : https://www.howtogeek.com/222532/how-to-repair-corrupted-windows-system-files-with-the-sfc-and-dism-commands/

Have you tried reinstalling your NordVPN ? It is possible a file in that is hanging/corrupted.

https://support.mozilla.org/en-US/kb/install-older-version-of-firefox

Or you can try a backup of your Profile and Bookmarks https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles Then a Refresh.

Or can create a new Profile after backing up and see if the old Profile is the cause of the issue. https://support.mozilla.org/en-US/kb/profile-manager-create-remove-switch-firefox-profiles

Boot the computer in Windows Safe mode with network support to see if that has effect in case security software is causing problems.

• http://www.bleepingcomputer.com/tutorials/how-to-start-windows-in-safe-mode/
• http://www.7tutorials.com/4-ways-boot-safe-mode-windows-10

Followed the first two directives and it seems to be working fine.

And, now it is not working again. Same issues as before. No matter whether I closed the VPN before or after closing the browser, I end up with three background processes in the task master. One of which cannot be ended by any other method than a reboot.

I know this happens because if I go back and reopen the browser it just hangs and nothing happens. As well, cCleaner doesn't do a clean of Firefox because it thinks it's still open. And, AdGuard freezes up.

I did the backup and refresh, and it still happened. I didn't reboot Windows to safe mode as I don't know what to do after the reboot. Function normally?

Again, this only started happening with the immediately previous version of Firefox. The one that fixed my previous issues with Flash player that was never resolved via these forums.

Hi, you have marked the question as solved so somewhere on your end to the right of that should be away to undo solved so that this goes back onto the active question board for others to see it so can help you. So if you could do that 1st.

I would think the issue is CCleaner cleaning to much out. Suggest going through CCleaner's settings/options and set it not to clean so much of Firefox and your VPN program.

Or exempt them from being cleaned and manually clean Firefox.

This is a usual issue with CCleaner.

Give that a try and let us know.

Ccleaner removes nothing in Firefox because the open process prevents it from cleaning it. It just skips over it. So, Ccleaner is not the problem.

Hi, you are running 2 versions of Flash : Shockwave Flash 29.0 r0 which is a security risk for being out of date and can cause conflicts with the other one installed : Shockwave Flash 32.0 r0

Please use Adobe Flash Uninstaller from here :

• https://helpx.adobe.com/flash-player/kb/uninstall-flash-player-windows.html

Note this will remove both versions and you can then reinstall Flash from here :

• https://get.adobe.com/flashplayer/

Back to the issue ; have you tested with both Firefox and NordVPN exempted from CCleaner ? What other cleaners are you running ? What are the other Extensions/addons that you are running please ? Think asked before but what antivirus/firewall are you running ?

Bill H said

Ccleaner removes nothing in Firefox because the open process prevents it from cleaning it. It just skips over it. So, Ccleaner is not the problem.

It still might be cleaning stuff out if you made a new Profile and was working fine as you say.

All problems when running CCleaner and Firefox is usually fixed by exempting it. Please try.

Thanks for the tip on Flash. I wasn't having any problems but did what you suggested, anyway.

As to Ccleaner, I don't think you are understanding me. If I have this hanging Firefox background process going on, Ccleaner doesn't touch it as it thinks it's still open. So, it skips it. It cleans the other browsers, etc. I have it set to clean after every browser shutdown. After this hanging Firefox background process happens, Ccleaner doesn't even run. Again, because it thinks Firefox is still open.

Remember, this is the background process that can't even be deleted through the Task Manager. Only way to kill it is with a reboot.

This morning, the attached happened. As well, I had the background process again after exiting the VPN and then closing Firefox in preparation to shut down the computer for a bit.

The only other cleaning-type software running is Malwarebytes (as suggested here) and AdGuard.

I use Norton 360 for security purposes - antivirus/firewall.

The only extensions running in Firefox are Norton Password and Mute Tab.

Again, I reiterate that I never had this problem, running everything noted above (other than Malwarebytes) until two versions ago (Firefox).

Oh, lastly, NordVPN cannot be excluded from Ccleaner. I can exclude Firefox, but then I end up with a very slow Firefox experience. Slower than it already is, especially after coming off NordVPN (likely because of this hanging background process).

BTW, while on NordVPN it's faster, though not as fast as before starting NordVPN. I'm on 250mbps Xfinity connection, FYI. Once I shut down NordVPN, Firefox slows to a crawl and most pages won't even load after 5 minutes.

Which, is why I then to the Task Master, only to always find this hanging background process mucking it all up. So, I reboot, and everything is working again and fast as ever.

Bill H said

Followed the first two directives and it seems to be working fine.

Where you said the above is it after booting Firefox into Safe Mode, is that correct ? If so then you were not running any extensions/addons while in Safe Mode.

You have not mentioned if you have tested afterwards by disabling all the extensions after starting Firefox back up out of Safe Mode. By Testing with them disabled then re enable 1 then test it can help pin down which extension is causing a issue.

I use Norton but not the Password Manager. It could possibly be that. so please test and report.

I mentioned uninstall NordVPN and reinstall it. Did you do that ? Did you let CCleaner clean before reinstalling ? If not maybe do so.

Could also try disable AdGuard and try another such as Ublock Origin

• https://addons.mozilla.org/en-US/firefox/addon/ublock-origin/

to see if AdGuard is the issue.

What type of system is this running on ? Processor and Ram & Motherboard if know please. Have you updated any of the Motherboard Drivers or returned them to Makers drivers after Windows10 changes them ?

• https://www.howtogeek.com/302595/how-to-stop-windows-10-from-automatically-updating-hardware-drivers/
• https://www.howtogeek.com/263851/how-to-prevent-windows-from-automatically-updating-specific-drivers/

Test lowering the processes Firefox is using (which lowers number in Task Manager) Note in this Article :

• https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems

below the Heading of Turn off hardware acceleration and below the red box you can adjust how many cores Firefox uses.

All in all if the issue is fixed when Firefox is in Safemode not sure what else to try other than the above.

Let us know.

While I thank you for all the responses, I really don't have the time to reboot my computer this many times to determine what the problem is with Firefox. This is the job of IAT, not UAT. I'll mark this as having solved the problem, though it hasn't. If it worked fine two upgrades ago, it should all work now. I've changed nothing to my software nor my processes, other than having added Malwarebytes at your behest. Again, IAT needs to figure this crap out, not UAT. I am the sole caregiver to an elderly dementia patient and have very little time for this constant back and forth testing things. If you had proper customer and tech service who could go into my system remotely and determine the problem instantly (like happened with NordVPN well before all this mishigas with Firefox), I'd stick with Firefox. But, that isn't the case. I've already migrated to Edge (Chrome had other, even worse, sync issues) and will remain there until the end of time. Sorry. I fully supported (other than financially, which maybe was the problem) Firefox in spirit and practice for several years. But, it let me down in the end.