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Firefox starts in task manager, but will not open a window.

  • 1 reply
  • 2 have this problem
  • 2 views
  • Last reply by FredMcD

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I saw a similar thread to this from 2015, but the difference here, is that it will start working if I end the task. So here's the deal, I have a windows 7 desktop, a windows 10 desktop, and a windows 10 laptop, and all 3 have this very strange problem, and all but one of the devices are running crisp, clean, unaltered, default, stock as a block firefox. No add ons or anything fancy. What will happen (usually on a fresh start up of the computer it seems, but will do it other times too) is I will click firefox (either on the desktop, or the locked taskbar icon) and nothing happens. Because I already know whats going on, I open task manager, and there will be 2 or 3 firefox tasks running (even if I only launch it once) . If I end all these tasks and launch firefox again, it will work, and keep working.

But every system I have has the same issue. Doesn't start the first time, and wont open the actual window unless you end the tasks and try again. I don't do custom install paths, I keep everything default. Firefox is usually the first thing I download and install onto a computer, so it shouldn't be any other programs messing with it.

Anyways, really bizarre problem that has apparently been around for a few years.

I saw a similar thread to this from 2015, but the difference here, is that it will start working if I end the task. So here's the deal, I have a windows 7 desktop, a windows 10 desktop, and a windows 10 laptop, and all 3 have this very strange problem, and all but one of the devices are running crisp, clean, unaltered, default, stock as a block firefox. No add ons or anything fancy. What will happen (usually on a fresh start up of the computer it seems, but will do it other times too) is I will click firefox (either on the desktop, or the locked taskbar icon) and nothing happens. Because I already know whats going on, I open task manager, and there will be 2 or 3 firefox tasks running (even if I only launch it once) . If I end all these tasks and launch firefox again, it will work, and keep working. But every system I have has the same issue. Doesn't start the first time, and wont open the actual window unless you end the tasks and try again. I don't do custom install paths, I keep everything default. Firefox is usually the first thing I download and install onto a computer, so it shouldn't be any other programs messing with it. Anyways, really bizarre problem that has apparently been around for a few years.

All Replies (1)

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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


https://support.mozilla.org/en-US/kb/changes-toolbars-and-window-sizes-are-not-saved You may have corrupt xulstore.json or Localstore.rdf file.

Close Firefox. Open your file browser to this hidden location:

  • Mac: *~/Library/Application Support/Firefox/Profiles
  • Linux: *~/.mozilla/firefox/Profiles
  • Windows: %AppData%\Mozilla\Firefox\Profiles
  • *C:\Users\<user>\AppData\Roaming\Mozilla\Firefox\Profiles
  • Windows XP: C:\Documents and Settings\<user>\Application Data
    \Mozilla\Firefox\Profiles\

Search for the above files. Then rename or delete them. Restart Firefox.

Modified by FredMcD