Please consider turning on send info to Mozilla from with in Firefox before posting a question. This helps us help you. I have no info from your system that would help see things that cause issues. Not even what version of Firefox .

There is security software like Avast/AVG, Kaspersky, BitDefender and ESET that intercept secure connections and send their own certificate.

• https://support.mozilla.org/en-US/kb/firefox-cant-load-websites-other-browsers-can
• https://support.mozilla.org/en-US/kb/firefox-and-other-browsers-cant-load-websites
• https://support.mozilla.org/en-US/kb/secure-connection-failed-error-message
• https://support.mozilla.org/en-US/kb/connection-untrusted-error-message
• http://kb.mozillazine.org/Error_loading_websites
• https://support.mozilla.org/en-US/kb/troubleshoot-SEC_ERROR_UNKNOWN_ISSUER

You may since running AVG which was bought by Avast need to go to their forum to find answers for the issues they create.

Can also do this : uninstall Firefox. Then Delete the Mozilla Firefox Folders in C:\Program Files , C:\Program Files(x86) & C:\ProgramData Then restart system. Then run Windows Disk Cleanup. (Note: This should be Pinned and run Weekly, If never done below expect 10's of gig's) Then run it again and click the button that says Cleanup System Files. Note: your Firefox Profile is saved. But you should make a back up before you do :

• https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles
• https://support.mozilla.org/en-US/kb/export-firefox-bookmarks-to-backup-or-transfer

Reinstall with Current Release Firefox 60.0.2 with a Full Version Installer

• https://www.mozilla.org/firefox/all/

Please let us know if this solved your issue or if need further assistance.

We uninstalled firefox totally including registry entries. We then uninstalled AVG then reisnatlled firefox When firefox is started it just has blank window there is no firefox logo on top left ,the menu items when clicked do nothing, clicking new tab creates a new tab that cannot be accessed. There is no way we can record or send info Anybody else with some ideas? This started after we ran disk clean up and Then updated firefox to latest version. P.S we also tried complete uninstall and reran previous version same behaviour after install. pulling my hair out now

As a test, disable AVG.

Some problems occur when your Internet security program was set to trust the previous version of Firefox, but no longer recognizes your updated version as trusted. Now how to fix the problem: To allow Firefox to connect to the Internet again;

• Make sure your Internet security software is up-to-date (i.e. you are running the latest version).
• Remove Firefox from your program's list of trusted or recognized programs. For detailed instructions, see

Configure firewalls so that Firefox can access the Internet. {web link}

avg disabled , firefox still load blank screens only cannot access options returns blank screen same in safe mode

Start your Computer in safe mode with network support. Then start Firefox. Try Secure websites. Is the problem still there?

http://encyclopedia2.thefreedictionary.com/Linux+Safe+Mode Starting Any Computer In Safe Mode; Free Online Encyclopedia

Nil help

i have resinsatlled firefox disabled avg and malware bytes still firefox refuises to connect to ineternte i jus get blank page and cannot access options it too results in blank page . i have tried everything am pullimg my hair out need to ge firefox working again HELP!

Well the good news....Win 10 updates with the October Update which will possibly fix the issue.

Try this : 1 ) Use the Windows key + X keyboard shortcut to open the Power User menu and select Command Prompt (Admin). 2) Type or Copy/Paste the following command and press Enter: 3) DISM /Online /Cleanup-Image /RestoreHealth 4) Reboot after.