Troubleshoot and diagnose Firefox problems
Revision Information
- Revision id: 10922
- Created:
- Creator: AliceWyman
- Comment: changed step 3 to Safe Mode troubleshooing - see https://support.mozilla.com/forums/knowledge-base-articles/705023
- Reviewed: Yes
- Reviewed:
- Reviewed by: AliceWyman
- Is approved? No
- Is current revision? No
- Ready for localization: No
Revision Source
Revision Content
Most problems with Firefox can be fixed by following the troubleshooting methods described below. Try these in order. If one doesn't work, move on to the next. If you need extra help with any of this, we have a community of volunteers standing by.
Table of Contents
1. Restart your computer
Sometimes problems can be fixed by simply restarting your computer and then starting Firefox again.
2. Clear your cookies and cache
Many problems with loading web pages can be resolved by clearing Firefox's cookies and cache:
- Click the menu button to open the menu panel.
- Click and select
- In the Time Range to clear: drop-down, select Everything.
- Below the drop-down menu, select both Cookies and Cache. Make sure other items you want to keep are not selected.
- Click .
3. Restart Firefox in Safe Mode
Diagnose Firefox issues using Troubleshoot Mode is a troubleshooting mode that disables extensions, uses the default theme, disables hardware acceleration and uses default toolbar settings and controls. All plugins remain enabled, however, and modified preferences are still used. To start Firefox in Safe Mode,
-
Click the menu button , click
, select and click in the Restart Firefox in Troubleshoot Mode? dialog.Note: You can also start Firefox in Troubleshoot Mode by holding down the Shift key while starting Firefox.holding down the option key while starting Firefox.quitting Firefox and then going to your Terminal and running:firefox -safe-mode
You may need to specify the Firefox installation path (e.g. /usr/lib/firefox). - In the Firefox Safe Mode dialog, click .
- Check whether your problem is still happening while in Safe Mode.
- If the problem still occurs in Safe Mode, skip the rest of this section and go on to step 4.
- If the problem goes away when you run Firefox in Safe Mode, use the steps below to narrow down the cause.
If the problem goes away in Safe Mode
Follow these steps:
- Troubleshoot extensions and themes. Switch to the default theme and disable all extensions. See Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems to learn how to narrow down which one is causing it.
- Reset toolbars and controls. It is also possible that the problem is being caused by a corrupt localstore.rdf file, which has to do with your toolbar settings and controls . To fix it, see this article.
- Disable hardware acceleration. It is also possible that the problem is caused by hardware acceleration. To disable this, remove the check mark in front of the option, "Use hardware acceleration when available" in your Firefox settings. See Options window - Advanced panel.
4. Update and troubleshoot your plugins
Sometimes plugins for Firefox (such as Adobe Reader, Flash, Java, QuickTime, RealPlayer, and Windows Media Player) can cause problems. Often this is because they are out of date. To check to see if you have the latest versions of all your plugins, go to our Plugin Check page:
- If any of your plugins are out of date, click and follow the instructions for updating that plugin.
- After you've updated all of your plugins, restart Firefox
- The template "closefirefox" does not exist or has no approved revision. Then start Firefox again.
If you are still having a problem after updating your plugins, it could be that you have a plugin that no longer works with Firefox. To see if this is the issue, disable all of your plugins. If the problem goes away, it's likely that a plugin is the cause:
- Click the menu button , click and select .
- Click each plugin in the list and then click .
- Check whether your problem happens when you have all plugins disabled.
If your problem goes away when all of your plugins are disabled, see the Troubleshoot issues with plugins like Flash or Java to fix common Firefox problems article to learn how to narrow down which one is causing it.
5. Reset Firefox's optionspreferences
If the problem was not fixed by disabling add-ons, you may need to reset all of Firefox's optionspreferences:
-
Click the menu button , click
, select and click in the Restart Firefox in Troubleshoot Mode? dialog.Note: You can also start Firefox in Troubleshoot Mode by holding down the Shift key while starting Firefox.holding down the option key while starting Firefox.quitting Firefox and then going to your Terminal and running:firefox -safe-mode
You may need to specify the Firefox installation path (e.g. /usr/lib/firefox). - In the Firefox Safe Mode dialog, click to put a check mark by Reset all user preferences to Firefox defaults and Reset toolbars and controls.
- To apply your changes, click .
6. Reinstall Firefox
Some Firefox issues can be caused by a problem with one of the Firefox program files. Follow these steps to completely remove and reinstall Firefox.
- Download the latest official version of Firefox from Mozilla.com.
- Exit Firefox: The template "closefirefox" does not exist or has no approved revision.
- Uninstall Firefox - see Uninstall Firefox from your computer for instructions. During the uninstalling process, do not select the option to Remove my Firefox personal data and customizations. You will lose all of your bookmarks, history, passwords and settings.
- After running the unistaller, be sure to also delete the Firefox installation folder which is located here by default: C:\Program files\Mozilla Firefox
- Reinstall Firefox - see How to install Firefox on Windows for instructions.
- Download the latest official version of Firefox from Mozilla.com.
- Quit Firefox: The template "closefirefox" does not exist or has no approved revision.
- Uninstall Firefox - see Uninstall Firefox from your computer for instructions. When following the uninstall instructions, do not perform the additional steps of removing user data and settings. You will lose all of your bookmarks, history, passwords and settings.
- Reinstall Firefox - see How to download and install Firefox on MacInstall Firefox on Linux for instructions.
Now start Firefox and check to see if your problem has been fixed. If it has, you can reinstall the extensions and themes you verified (in part 4 above) were not causing problems. If your problem hasn't been fixed continue with the next troubleshooting method.
7. Make a new profile
A bad profile can cause all kinds of problems with Firefox. To see whether your problem is caused by a bad profile, make a new one. If that fixes the problem, you can copy your data (bookmarks, saved passwords, etc.) over to the new profile.
- Use the instructions in the Profile Manager - Create, remove or switch Firefox profiles article to start the Profile Manager and create a new profile.When creating a new profile, do not delete your old profile. You will lose all of your bookmarks, history, passwords and settings.
- Once you've created a new profile, select it in the Profile Manager and click .
Test to see if your problem occurs with the new profile. If it doesn't, you can copy your data to the new profile - see Recovering important data from an old profile for instructions.
Other solutions
If you've tried all of these troubleshooting methods and you're still having problems the issue may be with other software or your Windows system.
Check for conflicts with your Internet security software
Some Internet security software (including antivirus, antispyware, and firewall programs) can cause problems with Firefox including blocking it from opening websites, crashes, and more. Often you can open the program's settings, remove Firefox from its list of allowed or trusted programs and it will be re-detected and things should start working again. If your program is listed at the Configure firewalls so that Firefox can access the Internet article, you can get specific instructions for how to properly reconfigure it.
Scan your system for viruses and spyware
Periodically, you should scan your system for viruses, spyware, or other malware. These free services are often useful:
Check your hard drive for errors
A problem with your computer's hard drive may prevent Firefox from running. Here are instructions for checking your hard drive:
Based on information from Standard diagnostic - Firefox (mozillaZine KB)