Firefox issues on Windows 10 & 11? Here’s how to fix them

Milan Stanojevic
by Milan Stanojevic
Windows & Software Expert
Milan has been enthusiastic about PCs ever since his childhood days, and this led him to take interest in all PC-related technologies. Before joining WindowsReport, he worked as a front-end web developer. Read more
Affiliate Disclosure
  • If you encounter Firefox issues on Windows 10 or 11, you should first check your extensions.
  • Certain applications can interfere with your browser, so you might want to disable them.
  • A corrupted cache or user profile often causes all sorts of problems with your browser.

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Firefox is known as one of the best browsers for the Windows platform, but unfortunately, it seems that Windows 10/11 users are having certain issues with it and now Firefox is not working for them.

There’s a wide array of issues that can occur, including slowdowns, crashes, and more, and all of these problems can affect your daily browsing activities.

However, there are several ways to fix them, and in today’s article, we’re going to show you a couple of methods that you can apply right away.

Why do Firefox issues appear?

In most cases, file corruption is the main cause. Your installation or cache can get corrupted, thus causing the issue. Other applications can also interfere with Firefox and lead to such problems.

It’s important to mention that sometimes your settings and even browser extensions can be the source of the problem.

What are some common Firefox issues?

Firefox issues can be problematic, and prevent you from using your browser. As for issues, we’ve compiled a list of common problems that users reported with Firefox:

  • Firefox won’t open – This issue can occur if there’s a problem with your Firefox profile. To fix it, simply recreate the profile.
  • Firefox too slow, using too much RAM – High RAM usage can occur due to your extensions, so be sure to disable all extensions that you don’t need and check if that helps.
  • Firefox high CPU usage – Sometimes high CPU usage can appear and cause issues with Firefox. This can be due to your antivirus, so be sure to disable it temporarily.
  • Firefox keeps crashing, freezing, not responding – Sometimes your configuration can cause problems with Firefox. However, you can fix that problem simply by starting Firefox in Safe Mode.

To learn more, be sure to check our Firefox Windows 11 issues article for additional information.

How do I fix Firefox not working on Windows 10 & 11?

1. Disable problematic add-ons

  1. Open Firefox and click the Menu button in top right corner. Choose Add-ons and themes from the list.
  2. Click the Extensions on the left. Now disable all extensions by toglilng the switch icon next to individual extensions.
  3. Restart Firefox and check if the issue is resolved.
  4. If the problem is fixed, you can try enabling extensions one by one until you find the one that is causing you problems.

According to some users, the add-on that caused the crash for them was FlashGet, but bear in mind that almost any add-on can cause Firefox to crash, so you might have to disable or remove certain add-ons to fix this issue.

In case you’re still having issues, you might want to consider switching to a different browser such as Opera.

2. Start Firefox in Safe Mode

  1. Locate the Firefox shortcut on your desktop, hold the Shift key and double-click it.
  2. When the dialog box appears, click the Open button.

After doing that, Firefox should start in Safe Mode. If the issue doesn’t appear in Safe Mode, it’s possible that one of your extensions or settings is causing this issue.

3. Check your antivirus

  1. Open Avast from and choose Settings in the bottom left corner.
  2. Choose Protection and navigate to Core Shields. Now uncheck Enable HTTPs scanning.
  3. Save the changes.

If you’re using a different antivirus solution, you might want to try disabling this or other similar features in it. In case that doesn’t work, your next step would be to completely disable or even uninstall it.

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After doing that, check our best antivirus software guide to find a reliable protection software that won’t cause any issues for you.

4. Reinstall Firefox

  1. Press Windows key + X and choose Apps and Features.
  2. Select Firefox on the list and click on Uninstall.
  3. Follow the instructions on the screen to complete the process.
  4. Once the software is removed, download the latest version and install it.

5. Clear your cache

  1. Click the Menu button in the top right corner and choose Settings.
  2. Navigate to Privacy & Security and click the Clear Data button.
  3. Make sure everythign is checked, and click on Clear.

6. Refresh Firefox

  1. Open Firefox.
  2. In the address bar enter about:support and press Enter.
  3. Click Refresh Firefox button.
  4. Click on Refresh Firefox and follow the instructions on the screen.

After you’re done, the Firefox should be restored to default and the problem will be permanently resolved.

7. Remove your Firefox profile

  1. Close Firefox.
  2. Now press Windows key + R and enter firefox.exe -p. Press Enter.
  3. A list of available profiles will appear. Select your user profile, it should probably be labeled as default and click the Delete Profile button.
  4. Now pick the desired option. If you want to completely remove your profile, click the Delete Files button.

After doing that, your profile should be removed, and a new one will be created once you start Firefox. You can also create a new profile from this dialog box. To do so, follow these steps:

  1. Click the Create Profile button.
  2. Click Next.
  3. Enter the desired name for your profile and click the Finish button.
  4. Now you just have to select the new profile and click the Start Firefox button.

After creating a new user profile, the issue should be completely resolved. Keep in mind that this method will remove your history, bookmarks, and saved passwords, so be sure to back them up beforehand.

8. Consider using Beta or Nightly version

  1. Visit the Firefox download page.
  2. Now click on Download next to the Beta or Nightly version.
  3. Once the application is downloaded, install it.
Note icon
NOTE
Beta and Nightly versions could be unstable, so you might experience certain issues while using them.

How can I fix Firefox issues on Windows 11?

Use Compatiblity mode

  1. Locate the Firefox shortcut and right-click it. Choose Properies from the menu.
  2. Navigate to the Compatiblity tab. Check Run this program in compatiblity mode for and select Windows 8 or older.
  3. Save the changes.

Why is Firefox slow?

If Firefox is running slow, the issue is most likely one of the open pages that you have. Complex pages use more resources, thus slowing down your browser.

We explored this issue before, and to learn more, head over to our Mozilla Firefox is too slow guide for more information.

Does Firefox use too much RAM?

Firefox is one of the lighter web browsers, and it doesn’t use too much memory in our opinion. We tested in on low-end PCs with just 4GB RAM and had no problems for the most part.

On a PC with more memory, the browser should run without any memory issues. Keep in mind that all other solutions from this guide apply to Windows 11, so feel free to try them.

Firefox issues on Windows 10 and 11 can be troublesome, and in most cases, these problems are caused by a third-party application or a Firefox extension.

In case you’re still having issues, we encourage you to visit our Firefox is not responding in Windows 10 and 11 guide for more solutions.

Do you know a different tip to solve this problem? If so, feel free to share it with us in the comments section below.

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Frequently Asked Questions

  • To remove malware from Firefox, press Ctrl + Shift + A to open the extensions page. From there, remove all suspicious extensions that you don’t recognize or remember installing.

  • Yes, Firefox has a Phishing and Malware protection feature that will provide you basic protection against malicious websites.

  • To reset Firefox, click the Menu icon and choose Help > Troubleshooting Information. Now click on the Refresh Firefox button and follow the instructions on the screen.