Multiple instances of “Phantom” Firefox running in background . . .
How can I eliminate the multiple occasions of Firefox running in the background? I’m running Firefox Quantum ver. 57.0.4 (64-bit). When I start Task Manager I find a huge number of instances of Firefox consuming huge quantities of resources, often 7 to 15 instances. None of these instances can be navigated to in order to stop them via Alt-Tab.
If I mouse over the lower toolbar (Win 7) to highlight the Firefox icon, sometimes it will show a list of web pages that I had been to many weeks ago, yet I can’t navigate to that occurrence by clicking on the item in the list. By the way, this dilemma occurred in previous versions of Firefox, also. So it doesn’t seem to be related to just Quantum.
I certainly hope this can be resolved because I have been a Firefox used for decades.
Chosen solution
Bud said
Sometimes, I will be typing in a blog or forum when another Phantom appears and steals the focus from the page I'm typing on. So, my post is simply cut off for half a sentence or so. Often Phantom after Phantom after Phantom appears listing themselves as pages I visited months earlier. I can never open these Phantoms, only navigate to the Windows bottom Toolbar, scroll over the Phantom and "X" out of it, or them.
It seems very suspicious. Have you scrutinized your add-ons lately? Do have any popup blocker add-ons to supplements Firefox's built-in popup blocker that could be doing an incomplete job?
You can view, disable, and often remove unwanted or unknown extensions on the Add-ons page. Either:
- Ctrl+Shift+a (Mac: Command+Shift+a)
- "3-bar" menu button (or Tools menu) > Add-ons
- type or paste about:addons in the address bar and press Enter/Return
In the left column of the Add-ons page, click Extensions.
Then cast a critical eye over the list on the right side. Any extensions Firefox installs for built-in features are hidden from this page, so everything listed here is your choice (and your responsibility) to manage. Anything suspicious or that you just do not remember installing or why? If in doubt, disable (or remove).
Any improvement?
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More than one process is normal for the current Firefox. http://www.ghacks.net/2016/07/22/multi-process-firefox/
Multi-process Firefox is codenamed "e10s". https://wiki.mozilla.org/Firefox/multiprocess
Try to disable multi-process tabs in Firefox.
You can disable multi-process tabs in Firefox by setting
the related prefs to false on the about:config page.
browser.tabs.remote.autostart = false browser.tabs.remote.autostart.2 = false
Type about:config<enter> in the address bar. If a warning screen comes up, press the I Accept the Risk button. At the top of the screen is a search bar.
I reset browser.tabs.remote.autostart = false browser.tabs.remote.autostart.2 = false
Actually, browser.tabs.remote.autostart was already set to false
It may take a while to see if this fixed the problem, but let me say, "Thanks" for your prompt response!
On the Processes tab in the Windows 7 Task Manager, you can add a column called Command Line which can help you distinguish between some of the firefox.exe processes. You'll need to make it pretty wide...
The ones with
-childID 1 -childID 2 -childID 3 etc.
are for web content.
Forgot to mention a control on the Options page related to the number of content processes: Firefox's performance settings.
After modifying about;config a instructed I exited Firefox and rebooted the computer. After starting Firefox I had one window open, yet when I mouse over the icon in the task bar, there is another "window" showing a site I ha visited quite some time in past. If I try to select that instance of Firefox it is all to no avail. I cannot "see" that window or that listed site.
When I opened Task Manager in the Applications Tab both instances of Firefox are shown, but in Processes Tab there was only one line item associated with Firefox. I added the additional column "Command Line" but it only shows C:/Mozilla Firefox/firefox.exe.
So, why does Firefox randomly pick web sites I have visited in weeks past to create these "Phantom" Firefox instances. Sometimes 7 or 8 at one time?
Modified by Bud
Reference, about;config
browser.tabs.remote.autostart.2 false
Hi Bud, when you hover your mouse over the Firefox icon on the Taskbar, and you get two thumbnails, can you "x" off the phantom window to close it, or does that not work?
There is an option to show a thumbnail for every single open tab. Could you make sure that is not set? You'll open the Options page:
- Windows: "3-bar" menu button (or Tools menu) > Options
- Mac: "3-bar" menu button (or Firefox menu) > Preferences
- Linux: "3-bar" menu button (or Edit menu) > Preferences
- Any system: type or paste about:preferences into the address bar and press Enter/Return to load it
Scroll down a bit to the Tabs section, and make sure this one is NOT checked: "Show tab previews in the Windows taskbar"
In the Task Manager, Processes tab, you're always going to see one firefox.exe for the user interface and one firefox.exe for the first web content tab. If the Command Line column is too narrow to see the difference, you may need to widen it by dragging the vertical line on the top right of the column header to the right.
Hi Bud, when you hover your mouse over the Firefox icon on the Taskbar, and you get two thumbnails, can you "x" off the phantom window to close it, or does that not work? Yes, I can "x" to close that window, but usually it is one of many and they are instantly replaced.
There is an option to show a thumbnail for every single open tab. These instances are not Tabs within the open Firefox Window. Could you make sure that is not set? You'll open the Options page:
- Windows: "3-bar" menu button (or Tools menu) > Options
- Any system: type or paste about:preferences into the address bar and press Enter/Return to load it
Scroll down a bit to the Tabs section, and make sure this one is NOT checked: "Show tab previews in the Windows taskbar"
In the Task Manager, Processes tab, you're always going to see one firefox.exe for the user interface and one firefox.exe for the first web content tab. If the Command Line column is too narrow to see the difference, you may need to widen it by dragging the vertical line on the top right of the column header to the right.
I'm running 64-bit Windows 7, if that matters. After yesterday's litany of possible fixes to this problem offered on this site the problem seems to have disappeared. Which of the numerous "fixes" corrected the problem is a good question. Currently in Task Manager there is only one firefox.exe, not two.
Well, this "Phantom Windows" issue seems to never, ever go away.
I have One Instance of Firefox running. I have two Tabs opened; Startpage and FVD Speed Dial. (I created a "Print Scr" to illustrate for you.) You can see those at the top of the photo.
I moved the mouse cursor to the bottom of the screen to bring up all the other instances of Phantom Firefox that appears there. I can't Click on any of them to enter that Window. I can "X" out in the upper right corner of each of these nonexistent instances if I want to that the time and trouble to do that all day, every day.
OK Firefox Guru's. What is going on here? This has been an issue for a long, long time now . . .
I'm concerned because Facebook involves personal information.
Are you able to view any of those Facebook windows by right-clicking the thumbnail and choosing Maximize?
Does it reduce the problem if you log out of Facebook (in a visible tab)?
If you have any add-ons that know your FB login (or have anything to do with FB), you could try disabling them to see whether that makes any difference in whether these windows open.
jscher2000 said
I'm concerned because Facebook involves personal information. Are you able to view any of those Facebook windows by right-clicking the thumbnail and choosing Maximize? Does it reduce the problem if you log out of Facebook (in a visible tab)? If you have any add-ons that know your FB login (or have anything to do with FB), you could try disabling them to see whether that makes any difference in whether these windows open.
No. I can't Open any of these 6 or 7 running instances.
Could you try opening a new FB tab and logging out, "x" off the other windows, and see whether it repeats?
Also, any FB-related add-ons?
A post was flagged as Solved Problem. If the problem is not solved, please remove that flag. If you don’t, others that can help may not read this post.
Go to that message, and use the Undo link to its right.
FredMcD said
A post was flagged as Solved Problem. If the problem is not solved, please remove that flag. If you don’t, others that can help may not read this post. Go to that message, and use the Undo link to its right.
My apologies. But, I have been trying to resolve this issue for a very long time. Occasionally, something seems to work, but it is very short lived. Today, I had 7 of what I call "Phantom Firefox" running simultaneously, not too long after I thought it was licked.
jscher2000 said
Could you try opening a new FB tab and logging out, "x" off the other windows, and see whether it repeats? Also, any FB-related add-ons?
What would I Log Out of?
jscher2000 said
Bud saidjscher2000 saidCould you try opening a new FB tab and logging out, "x" off the other windows, and see whether it repeats? Also, any FB-related add-ons?What would I Log Out of?
Are you not logged in? The thumbnails look like logged-in FB pages.
I am likely logged into a huge variety of "things" on the net. Which single thing do you want me to log out of?
Oh, Facebook!
Just for some historical perspective on this issue from my side of the keyboard let me say that I have had this dilemma for around a year. It tends to come and go, but mostly I have it to contend with.
Sometimes, I will be typing in a blog or forum when another Phantom appears and steals the focus from the page I'm typing on. So, my post is simply cut off for half a sentence or so. Often Phantom after Phantom after Phantom appears listing themselves as pages I visited months earlier. I can never open these Phantoms, only navigate to the Windows bottom Toolbar, scroll over the Phantom and "X" out of it, or them.
Often, after some advise I perform some action to correct this issue, thinking all was well. Then, in a few days or a week it returns. Having said that, I am hesitant to say "Issue Resolved."