J all the esr versions you mention are no no longer supported. Current versions 52.8.1 What ever error there was will remain as June 2018 as the final end of life date for Firefox support on Windows XP and Vista. Firefox 52.9.0esr out on June 26 (same time as 60.1.0esr) will be the last major update for Firefox 52 ESR apart from any 52.9.x esr updates for security or allowed stability fixes.

So glad your working fine with the version you installed.

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

thanks so much for your quick reply. do you mean that firefox 52.9 is the last version that support xp? is there any firefox 52.10 or more? because i read mozilla plans that xp is supported until september.

is there any specific settings in esr version that i can change and fix my issue for firefox esr permanently? i also reported my issue hear: https://bugzilla.mozilla.org/show_bug.cgi?id=1467684

zahra.a said

thanks so much for your quick reply. do you mean that firefox 52.9 is the last version that support xp? is there any firefox 52.10 or more? because i read mozilla plans that xp is supported until september.

Unless Mozilla decides to extend support for Firefox 52 ESR, the 52.9.x esr will be the last as it will be EOL as of September 5 when 60.2.0esr is Released. Firefox 53.0 and later on Windows including 60.0 Release and 60.0 ESR requires Windows 7, 8 (8.1), 10.

The only way you can use more current versions of Firefox on your old system would be to say dual boot with a light 32-bit Linux distro such as Xubuntu or Lubuntu among some others that still supports the old 32-bit CPU's.

thanks again for your support. but i studied hundreds of articles about linux and realized that the only operating system that can sutes my needs is windows! also my hardware is very old and i cant install two operating systems on it, so, i dont have any option other than windows! moreover, i dont need newer changes and features of firefox, firefox 51 or 52esr is sufficiend for me forever! but the problem is why firefox esr show error message when openning many https websites, while normal version (firefox 51), opens all the sites without a problem! is there any solution for this problem that makes using firefox esr version possible and without risk of error for me? or as i mentioned, i use firefox 51 forever and never update it! hear you are the error message which i recieve in esr version of firefox.

Secure Connection Failed The connection to bleepingcomputer.com was interrupted while the page was loading. The page you are trying to view cannot be shown because the authenticity of the received data could not be verified. Please contact the website owners to inform them of this problem.

as i mentioned, unfortunately i recieve this error (just in esr version of firefox), not for these websites that i mentioned, it affects many other https websites.

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/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

Errors can effect 1 browser and not another : Please 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, 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 52.8,1esr with a Full Version Installer

• https://www.mozilla.org/en-US/firefox/organizations/all/

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

as i mentioned, yesterday i realized that secure connection failed for me only affects firefox esr not regular version of firefox! before this discovery, i uninstalled and reinstalled firefox esr several times and none of them was successful. i mentioned that i never use and never trust any antimalware or antivirus program, so how can be related to antivirus program when i never use any of them? it is a new issue and i did not understand difference between firefox esr and regular version, so why it affects only esr version of firefox for me!

The VPN you're using might be behaving similarly to antivirus programs - that is, it may be intercepting your TLS connections. My guess as to why regular Firefox works while Firefox ESR doesn't is that the VPN knows how to add its root certificate to regular Firefox but not ESR. To be blunt, if your VPN is intercepting your TLS connections, it is not respecting your privacy and you probably shouldn't use it (unless you have to use it for work, I guess).

dkeeler said

The VPN you're using might be behaving similarly to antivirus programs - that is, it may be intercepting your TLS connections. My guess as to why regular Firefox works while Firefox ESR doesn't is that the VPN knows how to add its root certificate to regular Firefox but not ESR. To be blunt, if your VPN is intercepting your TLS connections, it is not respecting your privacy and you probably shouldn't use it (unless you have to use it for work, I guess).

So I guess the question is, if you uninstall the VPN, does ESR work?