Fix: Firefox has encountered an unexpected problem with Windows

by Megan Moore
Megan Moore
Megan Moore
Megan is a Windows enthusiast and an avid writer. With an interest and fascination in all things tech, she enjoys staying up to date on exciting new developments... read more
Affiliate Disclosure
  • Firefox users have reported receiving the error message: Firefox has encountered an unexpected problem with Windows.
  • This error may be caused by a faulty add-on or customization feature, running Firefox in Troubleshoot Mode may help locate the problem.
  • Always ensure your Windows PC and Firefox browser are up to date to avoid any bugs or issues.
Feature image Firefox has encountered an unexpected problem with windows.
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Mozilla Firefox is an open-source browser that is praised for its speed and security. The browser offers enhanced tracking protection and thus blocks third-party cookies by default.

However, users have reported receiving the error message Firefox has encountered an unexpected problem with Windows or a variation of it. Try the solutions listed below to solve this issue.

How do I fix the error: Firefox has encountered an unexpected problem?

1. Use a different browser

Opera browser integrated messaging.

If this issue has been happening consistently and you’re thinking about switching to another browser, we recommend Opera. This browser is open-source and operates on the Chromium engine. It has a user-friendly interface and offers built-in security features such as an unlimited VPN and ad-blocker.

Opera also has integrated messaging services from Facebook messenger, WhatsApp, and more. With workspaces, users organize their tabs by topic. This allows users to remain focused and productive while browsing.


Keep your tabs organized using workspaces in the Opera browser.

2. Check for updates

Make sure your Windows computer has the latest update installed. You can check for updates in settings under Windows Update. Also, be sure to check for any optional updates under Advanced options.

Check for updates in Firefox.

Firefox regularly releases updates for maintenance and improvements. Check that your Firefox browser is up to date in browser settings. Using an outdated version of Firefox or one that hasn’t been updated in a while might lead to performance issues and errors.

3. Disable add-ons

  1. Open Firefox and click the three lines in the top right corner to open the menu.
  2. Click Add-ons and themes. Firefox add-ons.
  3. Select Extensions. Open Firefox Extensions.
  4. Disable each add-on. Disable Firefox Extensions.

Users have reported the problem being solved after disabling their add-ons. If you’re using an extension that hasn’t been updated in a while or is faulty, then it’s recommended that you remove any unnecessary extensions.

4. Start Firefox in Troubleshoot Mode

  1. In Firefox click the three dots in the top right corner to open the menu and select Help. Firefox help settings.
  2. Click Troubleshoot Mode. Firefox Troubleshoot Mode.
  3. Selecting Open will start Firefox in its default form and temporarily disable all add-ons. Clicking Refresh Firefox will reset the browser to its default state and remove all customization features and extensions. Choose Open or Refresh Firefox in troubleshoot mode.

After choosing between Open and Refresh Firefox, test Firefox by visiting the site that was causing the issue.

If the problem is solved, then it was caused by one of your extensions or customization features. If the issue persists, then the error may be due to Firefox preference settings.

5. Reset Firefox preferences

  1. In Firefox click the three dots in the top right corner to open the menu and select Help.
  2. Select More Troubleshooting Information. Click on more troubleshoot information.
  3. Under Application Basics locate Profile Folder and click Open Folder. Under Application Basics open profile folder.
  4. Close Firefox.
  5. In the folder, locate the file prefs.js and delete it. If you want to keep it as a backup, you can simply rename it to prefsOLD.js. Delete prefs.js folder or rename it.

If you were still having the error Firefox has encountered an unexpected problem while in Troubleshoot Mode from the solution listed above, then try this solution. Resetting Firefox preferences may solve the problem.

6. Turn off hardware acceleration

  1. In Firefox click the three dots in the top right corner to open the menu and select Settings.
  2. Under General scroll down to Performance.
  3. Uncheck Use recommended performance settings to reveal more options. Scroll to Performance under General.
  4. Uncheck Use hardware acceleration when available. Disable hardware acceleration.
  5. Restart Firefox.

Firefox may have difficulties with certain websites when using the hardware acceleration. If the problem is solved after turning off the hardware acceleration, then try updating the graphics drivers or continue to use Firefox without it.

We hope these solutions solved the error Firefox has encountered an unexpected problem with Windows. If you’re having issues with your Firefox browser not responding at all in Windows, we have solutions for that as well.

Comment down below what solution worked for you. If there is a solution not listed above, be sure to let us know.

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