Troubleshooting Common Mozilla Firefox Errors – Reboot Strategies by ZDNet Experts

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The longer you use your web browser , the more likely it is that you’ll run into problems. It’s almost an inevitability. It’s also understandable. Once upon a time, browsers were only used for surfing the web. Today, we use them for everything. In fact, I’d go so far as to bet 90% of what 90% of people do on a computer is done via a web browser.

Because of that ubiquity, it should come as no surprise that our web browsers eventually give into the strain of what we put them through. And when you’re not regularly clearing your browser’s cache (and just generally treating them with care), they can crash and burn.

Also: How to customize the Firefox search tool to better fit your needs

When that happens, you have to take drastic measures. No, I’m not talking about uninstalling and reinstalling (although that can certainly do the trick) but, rather, resetting the browser. When you reset most web browsers, you lose all of your data , your bookmarks, passwords…everything. It’s as if you’ve installed the software for the first time. That way, you can be sure the browser will work as expected.

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However, a Firefox refresh doesn’t delete your bookmarks and passwords. Instead, it deletes all extensions and customizations (as those two bits are typically what cause problems for the browser).

Also: Firefox for Android just got an important privacy feature: How it could benefit you

The one thing I always suggest before doing this refresh is to make sure you’ve either backed up things like bookmarks or ensure you’ve joined your browser to a sync service. For example, with the Firefox browser, you can sign up for a free Firefox sync account and sync things like bookmarks, settings, open tabs, passwords, cookies, history, add-ons, credit cards, and addresses.

Once you’ve done that, when you reset Firefox, all you have to do is log in to your sync account and everything will sync. The caveat to this is that if, say, a particular setting or extension is what caused the problem, as soon as the sync finishes, you could find yourself back at square one. Because of that issue, I never add Settings or Add-ons to the list of synced items.

I would strongly recommend not syncing Settings and Add-ons.

Screenshot by Jack Wallen/ZDNET

Once you have your sync account set up, it’s time to do a refresh (aka “reset”) of Firefox.

How to refresh Firefox

What you’ll need: The only thing you’ll need for this is a running instance of the Firefox browser. I always recommend you use the latest version available, so make sure to upgrade the browser every chance you get.

1. Open Firefox

This, of course, assumes Firefox will open. If not, you’ll most likely have to uninstall and reinstall the application or remove your profile folder (more on that in a bit).

2. Open the Troubleshooting Information page

Click the Firefox menu in the upper right corner (three horizontal lines) and click Help > More troubleshooting information. Or you can simply type about:support in the address bar.

Accessing the troubleshooting window is done through the Firefox main menu.

Screenshot by Jack Wallen/ZDNET

3. Refresh Firefox

On the resulting page, click the Refresh Firefox button near the top right corner.

You can also use Troubleshoot Mode, which temporarily disables all add-ons, themes, and customizations.

Screenshot by Jack Wallen/ZDNET

4. Verify the refresh

A new popup window will appear. Click Refresh Firefox to verify the process. This will then delete the (possibly) offending bits and restart the browser. Once the browser has restarted, make sure to sign back in to your Firefox account and allow everything to sync.

Firefox won’t refresh until you click the required button.

Screenshot by Jack Wallen/ZDNET

What if Firefox won’t start?

If you find yourself in such a situation, you have two options:

Uninstall/reinstall Firefox
Rename your profile directory

I would suggest renaming your profile directory first. That way, when you re-open Firefox, it’ll create a new folder and you’re back to square one. Make sure to first close Firefox and then rename the directory in question, which is located in one of these places:

Linux (snap version): /home//snap/firefox/common/.mozilla/firefox/
Linux (non-snap version): /home//.mozilla/firefox
macOS: /Users//Library/Application Support/Firefox/Profiles/
Windows: C:\User\\AppData\Romaing\Mozilla\Firefox\Profiles\

Where is your username.

Within that folder, you’ll find a sub-folder with a random name. That’s your profile folder. Close Firefox, rename the folder, and re-open the browser. That should create a new profile folder and you’re back in business.

Also: What is Firefox Nightly and should you be using it?

Hopefully, you’ll never have to take such drastic measures. But should the occasion arise, you’re ready to take care of the situation.