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Firefox won't launch

  • 1 reply
  • 1 has this problem
  • 4 views
  • Last reply by cor-el

12pixelpete
12pixelpete
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When I try to launch Firefox, I get an error message that Firefox is running but not responding and buttons to Close Firefox or Cancel. Closing Firefox results in a pause, then the error message reappearing. When I monitor in Task Manager, I see 2 Firefox processes. One closes when I click Close Firefox, then reappears before the error message reappears. If I close both processes before launching Firefox, two new processes appear with the error message. I can't open Firefox in troubleshooting mode. I have uninstalled and reinstalled, still can't launch.

When I try to launch Firefox, I get an error message that Firefox is running but not responding and buttons to Close Firefox or Cancel. Closing Firefox results in a pause, then the error message reappearing. When I monitor in Task Manager, I see 2 Firefox processes. One closes when I click Close Firefox, then reappears before the error message reappears. If I close both processes before launching Firefox, two new processes appear with the error message. I can't open Firefox in troubleshooting mode. I have uninstalled and reinstalled, still can't launch.

All Replies (1)

cor-el
cor-el
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  • Top 10 Contributor
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You can check for issues caused by a corrupted or incomplete Visual C++ installation that is missing runtime components (Redistributable Packages) required by Firefox, especially VCRUNTIME140_1.dll.

See "Visual Studio 2015, 2017 and 2019":

You may also have to install the Visual Studio 2013 Redistributable Package. You need to reboot the computer.