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Firefox cannot start correctly error code 0xc0000142

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  • 1 has this problem
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  • Last reply by Scribe

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Hi When I start Firefox, I get an error "The Application Was Unable To Start Correctly (0xc0000142). Click OK to close the application".

If I install old Firefox versions, I can to start Firefox immediately after the install, but it automatically installs an update then I relaunch Firefox, I face the above 0xc0000142 error.

Please help.

Hi When I start Firefox, I get an error "The Application Was Unable To Start Correctly (0xc0000142). Click OK to close the application". If I install old Firefox versions, I can to start Firefox immediately after the install, but it automatically installs an update then I relaunch Firefox, I face the above 0xc0000142 error. Please help.

All Replies (1)

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Hi, this is a Windows error message.

Try performing a Clean reinstall. This means you remove your Firefox program files and then reinstall Firefox. This process does not remove your Firefox profile data (such as bookmarks and passwords), since that information is stored in a different location.

To do a clean reinstall of Firefox, please follow these steps:

  1. Using another browser, download the latest Desktop version of Firefox from this page) and save the setup file to your computer.
  2. After the download finishes, delete the Firefox installation folder, which is located in one of these locations, by default:
    • Windows:
      • C:\Program Files\Mozilla Firefox
      • C:\Program Files (x86)\Mozilla Firefox
    • Mac: Delete Firefox from the Applications folder.
    • Linux: If you installed Firefox with the distro-based package manager, you should use the same way to uninstall it - see Install Firefox on Linux. If you downloaded and installed the binary package from the Firefox download page, simply remove the folder firefox in your home directory.
  3. Now, go ahead and reinstall Firefox:
    1. Double-click the downloaded installation file and go through the steps of the installation wizard.
    2. Once the wizard is finished, choose to directly open Firefox after clicking the Finish button.

More information about reinstalling Firefox can be found here.

WARNING: Do not use a third party uninstaller as part of this process. Doing so could permanently delete your Firefox profile data, including but not limited to, extensions, cache, cookies, bookmarks, personal settings and saved passwords. These cannot be easily recovered unless they have been backed up to an external device! See Back up and restore information in Firefox profiles.

Please report back to say if this helped you!

Thank you.