firefox will not start. Cannot end process in task manager
As of this morning, I cannot get Firefox to work. I am using Windows 7. I click to start firefox and it looks like the program starts. It opens a Window with the minimize, maximize, and close buttons but the window contents are blank and the load icon appears. I can minimize and maximize the window but I cannot end the program. If I use CTRL-ALT-DEL, I can see that firefox.exe is running but I cannot end the task by selecting End Process. If I try to start another instance of Firefox, I get a warning box saying "Firefox is already running, but is not responding. The old Firefox process must be closed to open a new window."
Nothing I try will end the process.
I uninstalled and re-installed Firefox but the problem persists. I tried doing a fresh install with all previous add-ons and whatnot ignored but it still won't run. I've tried running it with the anti-virus disabled as well as with Windows in Safe Mode but it won't work.
Any ideas?
All Replies (20)
I can not open Firefox in safe mode
Modified by VeejUK
AVG support have been in contact I have sent them a AVG SysInfo data/logs as they have requested. Hopefully we can get a idea to whats causing this.
VeejUK said
vaclav.pich saidHi all thank you for patience, we contacted firefox to help us resolve the issue. Can you restart in safe mode and access about:crashes to get a crash ID ? Thank youI can not open Firefox in safe mode
If the Mozilla Crash Reporter came up and you submitted a report, there may be data available on disk. The folder location is mentioned in the latter part of this article: Firefox crashes - asking for support.
If Firefox hangs and needs to be killed externally, probably not.
Yes currently my Firefox is hanging and cannot be killed until I restart my machine. There is no crash report in the appdata folder. Once I restart my machine I will check again. Maybe it may create one.
Any other suggestions? Thanks
Mine is the same. I cannot run Firefox at all so I cannot access safe mode. There is no data log created.
Hi all I got the following email from AVG Support team today:
Unfortunately, we didn't reproduce the reported behavior. Our developers are already in touch with FireFox: https://bugzilla.mozilla.org/show_bug.cgi?id=1567144 and hopefully, it will be fixed soon. Your patience is much appreciated.
Hope this helps
Modified by VeejUK
SDRobot said
Yes, uninstalling Avast and then reinstalling Firefox seems to work.
Since this is an Avast issue, I'm going to mark this question "solved" based on the above. If you want to install another AV product, Microsoft Security Essentials is a good permanent antivirus for Windows 7. Windows 8/10 has Windows Defender antivirus protection built-in.
If you still want to use Avast, you may wish to follow this related Avast forum thread, https://forum.avast.com/index.php?topic=228355.15 Firefox v68.x hanging on start. Cannot end task via task manager ... and this bug report that was filed, Bug 1567144 Reports of Startup freeze when running Firefox alongside AVG or Avast
Doesn't solve the problem though. Guess I'll give that new Dissenter browser a try.
Agree with SDRobot, this tread should only be marked with solved once the issues gone.
I have now switched to Chrome.
SDRobot said
Yes, uninstalling Avast and then reinstalling Firefox seems to work.
The original question was, firefox will not start. Cannot end process in task manager. Does uninstalling Avast no longer solve that problem?
If the problem is that you cannot use Firefox with Avast, that's a different issue, being handled by Avast Support and reported to Mozilla in bug 1567144.
Modified by AliceWyman
I've been using Firefox since its inception and this is the first long term issue I've had with the browser. I've removed Avast! and switched to BitDefender but due to the inability to resolve the issue, I've also switched to Dissenter as my default browser.
SDRobot said
I've been using Firefox since its inception and this is the first long term issue I've had with the browser. I've removed Avast! and switched to BitDefender but due to the inability to resolve the issue, I've also switched to Dissenter as my default browser.
Would you please read my post about security software ? I hate to see people turn their back on Firefox, when Firefox isn't to blame for their problem(s).
I read it. I'd prefer to continue using Firefox as it's what I'm used to and I've got it configured the way I like but I don't feel Windows Security Essentials provides enough protection. I find Malwarebytes too predatory so im gking to try using Dissenter and BitDefender. So far I'm quite impressed with both. The biggest drawback with Dissenter is the inability to switch between search engines on the fly but apart from that, I am pleasantly surprised.
SDRobot said
I've removed Avast! and switched to BitDefender but due to the inability to resolve the issue, I've also switched to Dissenter as my default browser.
Can you clarify the current problem with Firefox and BitDefender? Is it the same issue (firefox will not start. Cannot end process in task manager) as with Avast or is it something different?
If it's a different problem and you still want to use Firefox, you may be better off starting a new support question (see Mozilla Support rules and guidelines under Posting support requests).
I'm running Windows 7 and have a similar problem. When I start firefox i get a totally unresponsive window. Also all applications seem to go in to slow motion, however taskmanager (TM) shows low cpu/memory usage. I can close the firefox window but it persists as a process in TM. I cannot kill the process with TM; I opened a win power shell in admin mode still couldn't kill it. I cannot even restart or shutdown. Although if i wait long enough perhaps shutdown will happen. I hit the power switch. I run microsoft windows essential. I recently scrubbed my hard drive and restarted with factory default Win 7. I'm fully updated. Firefox seemed to run ok for a couple of weeks. Then the nightmare began. I'm about to uninstall.
Hi pfitzsimmons, Firefox 68 uses a new technique to limit the ability of other programs to inject DLLs into the Firefox browser process. This seems to cause a deadlock with some security software.
I think Windows Essentials probably has been replaced with the latest Windows Defender, but I'm not sure. Is there any way to figure out what version you're running?
Could you mention any other security software on your system that could attempt to provide real time protection from browsers?
Nothing else but windows security essentials 4.10.209.0. I don't think MS supports defender on Win 7.
pfitzsimmons said
Nothing else but windows security essentials 4.10.209.0.
Hmm, that dates from around November 30, 2016. You could consider switching to something a bit more up-to-date. It's difficult to give a recommendation because we mostly hear about problems and incompatibilities.
But more generally, I don't know whether removing Windows Security Essentials would help with running Firefox.
I think I should just use a different browser because the support is total rubbish and they want us to find the answer for them. What a total waste of space and my time, a pity because I have used Firefox for years.
Hi tony.harrison999, I'm sorry you didn't find an answer to your question. Do you want to start a fresh thread and provide some information about your system and whatever problem you are experiencing?
https://support.mozilla.org/questions/new/desktop/fix-problems
Keep scrolling down past suggested articles and forum threads to continue with the form.