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.

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:

1. Click on the Tools menu and select Clear Recent History... to bring up the Clear Recent History window.
2. In the Time range to clear drop-down menu, select Everything.
3. Click the arrow next to Details to display the list of items to clear, then select the following items:
   • Cache
   • Cookies
4. Click Clear Now.

For more information, see Delete browsing, search and download history on Firefox.

3. 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 Often this is because they are out of date.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:

1. If any of your plugins are out of date, click Update and follow the instructions for updating that plugin.
2. 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:

1. Click the menu button , click Add-ons and themes and select Plugins.
2. Click each plugin in the list and then click Disable.
3. 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.

4. Troubleshoot your extensions and themes

Sometimes add-ons for Firefox (extensions or themes) can cause problems. To see whether your problem is caused by an extension or theme, disable them all by restarting Firefox in Diagnose Firefox issues using Troubleshoot Mode. If the problem does not happen in Safe Mode, it's likely that an extension or theme is the cause:

1. Click the menu button , click Help, select Troubleshoot Mode… and click Restart 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).
2. In the Firefox Safe Mode dialog, click Continue in Safe Mode.
3. Check whether your problem is still happening while in Safe Mode.

If the problem doesn't happen in Safe Mode, see Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems 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:

1. Click the menu button , click Help, select Troubleshoot Mode… and click Restart 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).
2. 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.
3. To apply your changes, click Make Changes and Restart.

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.

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.

1. 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 loose all of your bookmarks, history, passwords and settings.
2. Once you've created a new profile, select it in the Profile Manager and click Start Firefox.

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.

Based on information from Standard diagnostic - Firefox (mozillaZine KB)