User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:72.0) Gecko/20100101 Firefox/72.0

Steps to reproduce:

1. Install firefox update or fresh install.
2. After the update when firefox goes to open itself like it does after an update it will instead repeatedly open new tabs as new windows.
3. Same with fresh install and I removed all firefox folders including all the appdata ones.
4. Restart computer, same results as soon as I double click firefox shortcut.

Its been happening ever since v70.
Im able to constantly reproduce it and i can reproduce this issue on another computer as well.
I ran malware bytes to see maybe theres an infection came clean.
I7 6700k with 32 gigs of ram. Also on current build of windows 10 pro 1909.
Added exception for comodo as well.
The other computer I tested on does not have comodo only difference is specs.

Actual results:

Firefox will constantly open new tabs and windows until it crashes exploere.exe

Expected results:

When I install new or update i should not see a million tabs open in new windows crashing exploere.exe

I attached a firefox.zip file where i used windows psr to record it problem step recorder. So you could see visually what happens.

Also ran ccleaner for reg and clean out all cache files. Avira, adwcleaner and all came back clean.

Hi cubeteck1,
Try to create a new Firefox profile using the profile manager and see if it is still happening.
Here are steps to how to do that: https://support.mozilla.org/en-US/kb/profile-manager-create-remove-switch-firefox-profiles

HI timea,

I created a new one and will try to reinstall later tonite to update if creating a new one does anything different.

To add to this when I first went through a reinstall i deleted all app data folders called mozilla and looking at the setting looks like that is where the profiles are stored. The only thing i did when i did the first full reinstall was restore my old book marks that i backed up. Will that cause remnants of an old profile to be restored as well?

I don't have an account either with mozilla where you log in and can sync across devices.

Restored Bookmarks should not cause so many opened tabs upon launching Firefox, but its good to know them as a possible factor.
Let me know how the new profile procedure went.

Same results.

My thought is, its when Mozilla goes to open for the first time on install or update and you know how it likes to have two tabs open one saying the welcome thing and the other home, is what is causing it.

its only during thoes times it causes and endless loop of tabs crashes the exploere.exe and then I have to restart and hope I get luck with task kill and then mozilla is fine. But once I update back to square one. Me only fear is eventually I get a blue screen and windows will have to be reinstalled due to it.

Sorry for the late response, do you still encounter this issue?

I do still with every update or fresh install. After i get lucky with end task then it stops but takes a few restarts to get firefox out of the loop

(In reply to cubeteck1 from comment #8)

I do still with every update or fresh install. After i get lucky with end task then it stops but takes a few restarts to get firefox out of the loop

When it's not looping, can you go to Help > Troubleshooting Information, click the button labeled "copy raw data to clipboard", and paste it at https://bugzilla.mozilla.org/attachment.cgi?bugid=1607995&action=enter to attach it to this bug? Thanks!

TBH, I'm a bit stumped. The steps from comment #0 indicate that you've tried resetting/changing the default profile (though the screenshots indicate a configured profile? There's a theme and uBlock Origin installed and so on, which doesn't show up in the about:support data). The PRI shows that we start lots of new processes, and they all pop up the "Close firefox?" dialog because they detect another instance is running but (apparently?) they can't communicate with that instance.

How do you launch Firefox, and have you made any custom changes to registry settings for Firefox or the desktop/taskbar launcher icons?

:Mossop, any ideas about what would cause us to loop with that dialog?

:aklotz, the only clue I see in the about:support data is that the launcher process seems to have been force disabled. What can trigger that, and is it possible it relates to the previous point?

(In reply to :Gijs (he/him) from comment #11)

:aklotz, the only clue I see in the about:support data is that the launcher process seems to have been force disabled. What can trigger that, and is it possible it relates to the previous point?

That would have been set manually by the user; nothing triggers a force-disabled condition. Having said that, we probably shouldn't rule out launcher process issues, especially since the magic word "Comodo" appears in this bug.

ni? Toshi to add any thoughts.

It's not clear to me what we're looking at here. Is Firefox opening tabs, browser windows or something else? A full screenshot of the state would be helpful. The small part from the attachment suggests that we're hitting the failure to lock the profile on startup repeatedly which is pretty strange.

(In reply to Dave Townsend [:mossop] (he/him) from comment #13)

It's not clear to me what we're looking at here. Is Firefox opening tabs, browser windows or something else? A full screenshot of the state would be helpful. The small part from the attachment suggests that we're hitting the failure to lock the profile on startup repeatedly which is pretty strange.

You can see a series of screenshots if you open the .mht from the zipfile with IE on a Windows machine. They seem to show a large number of processes that have all opened the "Close Firefox" dialog.

Hi All,

1. How do you launch Firefox, and have you made any custom changes to registry settings for Firefox or the desktop/taskbar launcher icons?

I launch it from the shortcut that gets made after an install. Only changes i do is under properties and compatibility tab I check the box run as administrator.
No registry hacks. Only thing I though about doing is going through registry after an uninstall of Mozilla to delete entries but i know restoring from a backup of the registry if you mess something up never works.

2. (though the screenshots indicate a configured profile? There's a theme and uBlock Origin installed and so on, which doesn't show up in the about:support data).

Dont have a profile or one i sign in with but once I get mozilla out of the loop its in, I do install ublock and do a custom theme. Only thing else I do is change search engine to default google. But for the testing I just been installing it new and then uninstalling it after i get what logs you guys want, I also delete all app folders and program file folders as well.

I do know last time I installed it, it did lock up my computer and had to recovery from windows. I'm ok with testing more as i made a recent img to restore if it does not recovery at all next time.

3. the only clue I see in the about:support data is that the launcher process seems to have been force disabled. What can trigger that, and is it possible it relates to the previous point?
   That would have been set manually by the user; nothing triggers a force-disabled condition. Having said that, we probably shouldn't rule out launcher process issues, especially since the magic word "Comodo" appears in this bug.

Where does one set that? I never heard of this setting. As far as comodo goes i put firefox as a trusted app and under shell code injections i flagged the whole folder as does not scan at all, granted having to uninstall so I can reinstall to reproduce might undo my changes with in comodo as the folder as i delete the folder now but even just upgrading triggers it as well with comodo maintain the settings as the folder would exist. I can try sometime this weekend stopping comodo complete and then try installing firefox to see if it is indeed interfering.

As a heads up It might be monday when I respond due to not sure if windows will recover if my machine does lock up and I have to reinstall with the image.

Now that I think about it, I dont need to test disabling comodo as my dads computer exhibits the same issue as mine but he does not have comodo installed. I did try last time I was over to reinstall and it did the same thing.

(In reply to cubeteck1 from comment #15)

I launch it from the shortcut that gets made after an install. Only changes i do is under properties and compatibility tab I check the box run as administrator.

Why do you choose to run it as administrator? Does the same issue occur if you don't to this? Without testing for sure I can think of a few problems that this might cause.

(In reply to cubeteck1 from comment #15)

3. the only clue I see in the about:support data is that the launcher process seems to have been force disabled. What can trigger that, and is it possible it relates to the previous point?
   That would have been set manually by the user; nothing triggers a force-disabled condition. Having said that, we probably shouldn't rule out launcher process issues, especially since the magic word "Comodo" appears in this bug.

Where does one set that? I never heard of this setting. As far as comodo goes i put firefox as a trusted app and under shell code injections i flagged the whole folder as does not scan at all, granted having to uninstall so I can reinstall to reproduce might undo my changes with in comodo as the folder as i delete the folder now but even just upgrading triggers it as well with comodo maintain the settings as the folder would exist. I can try sometime this weekend stopping comodo complete and then try installing firefox to see if it is indeed interfering.

Launcher process is this. In your data, launcherProcessState is set to 2 which means ForceDisabled. It can be set manually through about:config, but also any program can set it through registry. So if you don't do any registry hacks, a third-party app (not sure comodo does that), did it. However, I have no idea what can cause this kind of an infinite loop of starting a process, especially without the launcher process, and from multiple computers..

As Dave suggested above, I'm also curious what happens without running as admin. I'm also curious how the process hierarchy looks like when this happens.

Edit: Moved to bug attachment 9127080 [details].

Good morning all,

Sorry for the spam I copied the raw data again for this test as well. Ill put that in a text file next time as well.

Just tried it same thing happens. This time i did not launch firefox with admin checked and I also disabled comodo and defender from scanning same results. But it only to a restart of windows exploere.exe to stop it and now it works. Ill leave it installed if there is any more info needed but if not let me know and ill uninstall so we can try other ideas.

(In reply to cubeteck1 from comment #20)

Sorry for the spam I copied the raw data again for this test as well. Ill put that in a text file next time as well.

No worries, I moved it to an attachment for you to keep the bug easy to follow.

Just tried it same thing happens. This time i did not launch firefox with admin checked and I also disabled comodo and defender from scanning same results. But it only to a restart of windows exploere.exe to stop it and now it works.

Can you elaborate a bit? Do you mean the problem is gone now? I'm also confused as to why a restart of explorer.exe would fix anything here, but perhaps Dave or :toshi would have ideas about that...

These are steps I've done to get Firefox out of the loop from either new install or update:

1. taskkill in cmd prompt.
2. Restart windows exploere.exe with in task manager.
3. Using task manger to end one of the many Firefox processes running.
4. After either one (upgrade or fresh install) I wait and windows will restart windows exploere.exe after it crashes.
5. Sometimes when firefox in the loop, it will lock up my computer and have to restart to try one of the above steps again.

Through all the testing it would seem to be tied to windows explore.exe needing a restart or windows it self restarting it after it crashes.
(I'm not sure it just something I try among the other steps that have worked and I noticed that a couple of them I've seen and tried deal with windows explore.exe)

Once I get firefox out of the loop with one or many of the steps above, I can then use firefox normally without any problems but upon an update to firefox where back to the loop and have to go through and try to get it to stop again with the above steps.
(I've narrow it down to either a new install of firefox, like I been doing to test or with an update to firefox, that will trigger firefox loop)

Regards,

Hi cubeteck1,
Is this still reproducible on the latest Firefox version?

(In reply to Timea Cernea [:tbabos] from comment #24)

Hi cubeteck1,
Is this still reproducible on the latest Firefox version?

I just tested updating and it did not do it for firefox version 74 :D. I will test a fresh install though to see if that still triggers it later this weekend.

(In reply to :Gijs (he/him) from comment #22)

Can you elaborate a bit? Do you mean the problem is gone now? I'm also confused as to why a restart of explorer.exe would fix anything here, but perhaps Dave or :toshi would have ideas about that...

The only thing I can think of is that for some reason explorer.exe has a lock on the thing we try to lock when starting up.

(In reply to Dave Townsend [:mossop] (he/him) from comment #26)

(In reply to :Gijs (he/him) from comment #22)

Can you elaborate a bit? Do you mean the problem is gone now? I'm also confused as to why a restart of explorer.exe would fix anything here, but perhaps Dave or :toshi would have ideas about that...

The only thing I can think of is that for some reason explorer.exe has a lock on the thing we try to lock when starting up.

So far with v74 and v75 updates, through auto update in mozilla I have not been able to reproduced the issue :D. I still have yet to try a full reinstall of mozilla to test that as well been busy sadly. I'll try to get that done this weekend.

(In reply to :Gijs (he/him) from comment #22)

Can you elaborate a bit? Do you mean the problem is gone now? I'm also confused as to why a restart of explorer.exe would fix anything here, but perhaps Dave or :toshi would have ideas about that...

Sorry for not responding to this for long. We delegate explorer.exe to launch a new process if the process is launched with high IL. I thought if explorer.exe was running with high IL, this kind of launching loop might happen, but in my understanding Win10 does not allow explorer.exe to be launched with high IL..

So did a fresh install of firefox and i'm happy to report I'm not able to reproduce the issue with v75.

I'm not sure what the difference between firefox v70 - v73 which caused the issue no matter what I did I was able to consistently reproduce it. With firefox versions v74-v75 I'm unable to reproduce it.

Not sure if maybe there was a windows update in between all the testing that may have address it, since i update windows every second Tuesday update day.

Or

If something has changed between v73 to v74. I'll keep testing as I know we have a huge update this Tuesday going to windows 10 build 2004 going live. I'll try another fresh install next week and then wait for another update to come out as well for firefox to test that to.

The only thing I can think of trying is doing my usual thing of restoring book marks, add ublock origin, and then add a custom theme. To see if that some how creates issues with a reinstall and keeping my settings.

I know i have over 1k book marks with lots of sub folders exact number 1140 and number of folders 48.

Going to tentatively resolve this as "works for me" given comment #29 seems to indicate this has been fixed - we can reopen if this happens again.