FIX: Firefox Couldn’t Load XPCOM Error

XPCOM stands for Cross-Platform Component Object Model. It is a component of Mozilla. Firefox cannot function properly without XPCOM.

If this component is missing, you will get the couldn’t load the XPCOM error. One of the prominent causes for this error is a failed Firefox update.

Follow this guide as here I have discussed how to fix the error quickly.

Also read:

What To Do When Firefox Couldn’t Load XPCOM?

When Firefox couldn’t load XPCOM, follow the methods explained below.

1) Run Firefox As An Administrator

When Firefox is unable to load XPCOM, run Firefox as an administrator.

Allowing administrative privileges to Firefox web browsers can fix these types of errors.

To run Firefox as an administrator, follow the steps below:

  • Right-click on the Firefox desktop icon. Select Properties.
  • Click on the Compatibility tab. Check the box for Run this program as an administrator.  Save the changes by clicking on the Apply button followed by OK.


Run Firefox and if the problem persists, go to the next solution.

2) Create A New Firefox Profile

If running Firefox as administrator doesnt fix the XPCOM error, then create a new Firefox profile.

To do that, follow the steps given below:

  • Open Firefox and type about:profiles in the address bar. This will open the About Profiles settings of Firefox.
  • Select the Create a New Profile option.


  • Create Profile Wizard will open on your screen. Click on Next.
  • Name the profile. You can also change its location but I would recommend to save it in the default location. Click on Finish.
  • After the profile is created, scroll down and locate the profile. Now you can either launch it in a separate window or set it as default.


Now check if the problem is solved in the new profile. If the issue persists, go to the next solution.

3) Reinstall Thunderbird

If you couldn’t load XPCOM on Thunderbird, then reinstall Thunderbird.

To do so, follow the steps given below:

  • Enter the Control Panel in the Windows search box and select the top option.
  • Select Programs and Features.


  • Click on the Uninstall a program option and find Mozilla Thunderbird from the list of installed apps.
  • Select the Yes button and follow the onscreen instructions to finish the process.
  • Click here and download Thunderbird. Follow the onscreen instructions to finish the process.

4) Reinstall Firefox

The installation files of Firefox can become corrupted and cause the XPCOM error.

Reinstall Firefox and see if that solves the problem. Here is how you can do it:

  • Open Run utility and enter appwiz.cpl in the command box. Press the Enter key.


  • Look for Firefox among the installed apps and right-click on it.
  • Click on the Uninstall option from the menu. To complete the uninstallation process, follow the on-screen prompts.


  • Next launch the Run utility and enter %temp% in the Run command box.


  • Press the Enter key. Delete everything in the temporary folder.
  • Now, download it again from their official website.

Open Firefox and check if the problem is solved. If not, then go to the next solution.

5) Disable Firewall Or Antivirus Program

Sometimes Firewall or your antivirus can interfere with Firefox and create problems.

So, disable the Firewall temporarily following the steps given below:

  • Enter Windows Defender Firewall in the Windows search box and select the top option.
  • From the next window, click on the Turn Windows Defender Firewall on or off option.


  • Next, click on the radio buttons for Turn off Windows Defender Firewall. Make sure to do this for both Private and Public network settings.


If you use any 3rd party antivirus program, make sure to you are using any other antivirus program; make sure to disable that.

Your device is vulnerable to threats after you disable the Firewall and antivirus program, so remember to turn them on later.

Closing Up

If the above article was helpful to you when Firefox couldn’t load XPCOM on your PC, then tell us in the comment section.

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Sanchita Das
Sanchita Das
Creative and focused. Always ready to learn new techniques and improvise accordingly. Loves to meet new challenges and explore new possibilities.


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