Hello,

The Refresh feature (called "Reset" in older Firefox versions) can fix many issues by restoring Firefox to its factory default state while saving your bookmarks, history, passwords, cookies, and other essential information.

Note: When you use this feature, you will lose any extensions, toolbar customizations, and some preferences. See the Refresh Firefox - reset add-ons and settings article for more information.

To Refresh Firefox:

1. Open the Troubleshooting Information page using one of these methods:
   • Click the menu button , click help and select Troubleshooting Information. A new tab containing your troubleshooting information should open.
   • If you're unable to access the Help menu, type about:support in your address bar to bring up the Troubleshooting Information page.
2. At the top right corner of the page, you should see a button that says "Refresh Firefox" ("Reset Firefox" in older Firefox versions). Click on it.
3. Firefox will close. After the refresh process is completed, Firefox will show a window with the information that is imported.
4. Click Finish and Firefox will reopen.

Did this fix the problem? Please report back to us!

Thank you.

And my settings, extensions list, etc. will not suffer from this?

You can be sure most people do not see this sort of problem. It will be something to do with your use or install of Firefox.

Yes that will remove your extensions and change some other things. An alternative troubleshooting method is to try out Firefox in a new additional profile and in Firefox's safemode. That will not harm your current install or lose any extensions or settings.

If you see improvements it will help provide clues in trying to identify what the problem is.

See

• Diagnose Firefox issues using Troubleshoot Mode
• Profile Manager - Create, remove or switch Firefox profiles
• Firefox hangs or is not responding - How to fix

Also see

• Quick fixes if your Firefox slows down
• Firefox uses too much memory or CPU resources - How to fix
• Firefox uses too much memory or CPU resources - How to fix
• Troubleshoot Firefox crashes (closing or quitting unexpectedly)
• Send plugin crash reports to help Mozilla improve Firefox

By the way is this problem apparently related to

• Having very many Tabs open
• Playing videos &/or FlashPlayer

There are advanced methods of troubleshooting hangs, but believe me the simplest and quickest initial method is the Refresh OR to use a new profile in safemode and with all plugins disabled; and work up from there.

Unfortunately, nothing helped. Something can still advise?

Are you saying after a refresh Firefox hangs frequently for about 1/2 an hour in safemode with plugins disabled and with only a couple of tabs open ?

That would be unusual and obviously a very bad experience.