We're calling on all EU-based Mozillians with iOS or iPadOS devices to help us monitor Apple’s new browser choice screens. Join the effort to hold Big Tech to account!

Pesquisar no apoio

Evite burlas no apoio. Nunca iremos solicitar que telefone ou envie uma mensagem de texto para um número de telefone ou que partilhe informações pessoais. Por favor, reporte atividades suspeitas utilizando a opção "Reportar abuso".

Saber mais

I hated 4.0, so I reinstalled 3.6 and it won't open. What do I do now?

  • 3 respostas
  • 4 têm este problema
  • 7 visualizações
  • Última resposta por cor-el

more options

I uninstalled 4.0 and reinstalled 3.6 using there instructions from your forum...

If you still want to downgrade to Firefox 3.6.* you can uninstall Firefox 4, but do not select the option to "Remove my Firefox personal data". If you select that option it will delete your bookmarks, passwords and other user data.

You can then install Firefox 3.6.* available from http://www.mozilla.com/en-US/firefox/all-older.html - it will automatically use your current bookmarks, passwords etc.

To avoid possible problems with downgrading, I recommend going to your profile folder and deleting the following files if they exist - extensions.cache, extensions.rdf, extensions.ini, extensions.sqlite and localstore.rdf. Deleting these files will force Firefox to rebuild the list of installed extensions, checking their compatibility, and reset toolbar customizations.

For details of how to find your profile folder see https://support.mozilla.com/kb/Profile

The reinstall of 3.6 won't open. What do I do now???

I uninstalled 4.0 and reinstalled 3.6 using there instructions from your forum... If you still want to downgrade to Firefox 3.6.* you can uninstall Firefox 4, but do not select the option to "Remove my Firefox personal data". If you select that option it will delete your bookmarks, passwords and other user data. You can then install Firefox 3.6.* available from http://www.mozilla.com/en-US/firefox/all-older.html - it will automatically use your current bookmarks, passwords etc. To avoid possible problems with downgrading, I recommend going to your profile folder and deleting the following files if they exist - extensions.cache, extensions.rdf, extensions.ini, extensions.sqlite and localstore.rdf. Deleting these files will force Firefox to rebuild the list of installed extensions, checking their compatibility, and reset toolbar customizations. For details of how to find your profile folder see https://support.mozilla.com/kb/Profile The reinstall of 3.6 won't open. What do I do now???

Todas as respostas (3)

more options

The directions you posted look good to me, though I would not have deleted the files, there is no harm, Firefox will recreate them.

I expect that you have an extension that is bad probably one bad enough to be listed in

or listed in the blocklist


I would suggest going back to Firefox 4.0.1 and trying to fix your problems there. In either case you will need to open in Firefox Safe Mode, see Safe Mode - MozillaZine Knowledge Base which will disable extensions and I would expect that you would be able to run Firefox that way. If you can run okay only in Safe Mode then that almost certain means an extension problem.

If you can use menus but not use "Enter" on the location bar that proably points to "AVG Safe Search" extension and you would have to follow directions in Problematic extensions to reinstall AVG Free without the Link Scanner Component. If you can't easily identify the extension causing problems then see


Firefox 4.0 is not a problem you thought it was, since you can customize the appearance.

You can make Firefox 4.0.1 look like Firefox 3.6.17, see numbered items 1-10 in the following topic problems.htm#fx4interface Fix Firefox 4.0 toolbar user interface, problems (Make Firefox 4.0 look like 3.6)

Modificado por David McRitchie a

more options

Yeah, gee thanks for continuing to pimp 4.0.1. That's really helpful. Fortunately, I have a geek friend who helped me get up and running again. Don't ask me what he did, but I am happily back on 3.6. I no longer have stalls, crashes and a terrible Internet connection. I can stream again and I am zooming just like I was before.

This unstable 4.0 piece of garbage made my computer act like it was infested with a horrible virus or something. I ran a virus scan and a malware scan and there was nothing significant. That's what made me wonder if if was your shiny new release that was choking out my machine. Yep, it was.

Perhaps you should do more extensive testing on older machines before strong-arming people into switching to a new version. I have a 3-year-old HP laptop, running XP. I will NOT be using 4.0.

Do I sound bitter? I am. I wasted a week and a half of not being able to function while blaming my IP and non-existent bugs. That's time I can't recover. So thanks. Good job!

more options

Did you check your security software (firewall)?

A possible cause is security software (firewall) that blocks or restricts Firefox or the plugin-container process without informing you, possibly after detecting changes (update) to the Firefox program.

Remove all rules for Firefox from the permissions list in the firewall and let your firewall ask again for permission to get full unrestricted access to internet for Firefox and the plugin-container process.

See: