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firefox doesn't work after updating 43.0.4

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Latest upgrade 43.0.4 won't let me browse website. Tried everything in https://support.mozilla.org/en-US/questions/1103440?utm_campaign=questions-solved&utm_medium=email&utm_source=notification#answer-828839 as well as disabling firewall. Tried creating new profiles, etc. This is frustrating and making me want to move to another browser.

Latest upgrade 43.0.4 won't let me browse website. Tried everything in https://support.mozilla.org/en-US/questions/1103440?utm_campaign=questions-solved&utm_medium=email&utm_source=notification#answer-828839 as well as disabling firewall. Tried creating new profiles, etc. This is frustrating and making me want to move to another browser.

All Replies (5)

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hello, usually such issues are caused by a firewall/security software which doesn't recognize & therefore blocks new firefox versions. please remove all program rules for firefox from your firewall and let it detect the new version of the browser again.

Fix problems connecting to websites after updating Firefox

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I turned off firewall. Tried. Still can't connect to websites. Even turned off firewall and set to not load at start. Turned off computer to wipe memory and then turned back on. Same problem. I removed all Firefox processes from firewall settings and then did same shut down and restart.

Modified by FrustratedUser1

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Start Firefox in Safe Mode {web Link} by holding down the <Shift>
(Mac=Options)
key, and then starting Firefox. Is the problem still there?


Start your Computer in safe mode with networking. Then start Firefox. Try Safe web sites. Is the problem still there?

Starting The Computer In Safe Mode;
Free Online Encyclopedia

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Do a clean reinstall and delete the Firefox program folder before (re)installing a fresh copy of the current Firefox release.

If possible uninstall your current Firefox version to cleanup the Windows registry and settings in security software.

  • Do NOT remove "personal data" when you uninstall your current Firefox version, because this will remove all profile folders and you lose personal data like bookmarks and passwords including data in profiles created by other Firefox versions.

Remove the Firefox program folder before installing that newly downloaded copy of the Firefox installer.

  • (32 bit Windows) "C:\Program Files\Mozilla Firefox\"
  • (64 bit Windows) "C:\Program Files (x86)\Mozilla Firefox\"

Your personal data like bookmarks is stored in the Firefox profile folder, so you won't lose personal data when you uninstall and (re)install or update Firefox, but make sure NOT to remove personal data when you uninstall Firefox as that will remove all Firefox profile folders and you lose your personal data.

If you keep having problems then create a new profile.


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So... tried all of the above with the exception of loading windows in safe mode with networking as can't find this in the new windows 10. None of it worked. I ended up doing a system restore from before the upgrade. Firefox is working again, but is version 43.0.3. I have turned off automatic updates as don't want to upgrade and lose firefox again....

I should also state that firefox could load when upgraded, but couldn't connect to any webpages.