There is no mozilla.com it is .org Please try : 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 59.0 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.

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}

I have tried both 'fixes' but I still get the same message that *** has not configured their website properly, this apples to mozilla.org as well. I think that I am going to have to give up using Firefox.

I use BullGuard but turning off the Firewall makes no difference.

Start Firefox in Safe Mode {web link} by holding down the <Shift> (Mac=Options) key, and then starting Firefox.

A small dialog should appear. Click Start In Safe Mode (not Refresh). Is the problem still there?

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

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

Starting Firefox in Safe Mode made no difference. My computer does not appear to want to start up in safe mode. I have tried holding down the F8 key, started up as normal. Held down the Shift key, as recommended for Windows 10, started as normal. I still have the same problem with Firefox.

FredMcD said

Start Firefox in Safe Mode {web link} by holding down the <Shift> (Mac=Options) key, and then starting Firefox. A small dialog should appear. Click Start In Safe Mode (not Refresh). Is the problem still there?

What happened when you tried Firefox in it's Safe Mode ?

Please also do this : Windows 10 To run the DISM command use the Windows key + X keyboard shortcut to open the Power User menu, then select Command Prompt (Admin). Type "DISM /Online /Cleanup-Image /RestoreHealth" (without quotes or copy/paste) and press Enter. Reboot After.

I tried Firefox in safe mode and it made no difference. Windows + X brought up a menu but there was no 'Command Prompt (Admin)'. There was a 'Windows Powershell (Admin) which brought up a basic file. I typed in DISM etc, hit return, a lot of red text, then I rebooted. I opened Firefox but exactly the same response when trying to open bank website.

Sorry to hear did not work, Please try : 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(Win10)) 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 59.0 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.

Gordon_B said

I use BullGuard but turning off the Firewall makes no difference.

Try the setting mentioned in our support article: How to troubleshoot security error codes on secure websites.

For background, what the program does is intercept your browsing to filter it for threats (I assume). In order to do that, as a man in the middle, to be able to read your secure sessions, it must present fake website certificates to your browsers. Firefox doesn't use the Windows certificate store; it has its own. If the security software doesn't add its signing certificate to Firefox's store, none of its fake certificates will be trusted by Firefox.

Options:

(1) Turn off that feature, or turn it off only for Firefox, if possible (see the above article)

(2) Import the Bullguard signing certificate into Firefox so Firefox trusts its fake certificates -- you could ask on Bullguard's forums if they have instructions for that

(3) Change Firefox's trust settings to piggyback on whatever Windows trusts (sacrificing the additional protection of having an independent certificate store) -- we can give steps for this if needed

My BullGuard subscription has just run out. There was a short period before it was renewed and Firefox worked OK in this period. Now it has been renewed, I am back to the same problem. Thus I believe BullGuard is the problem. I have tried the procedure in the support article but it does not reflect what I get in BullGuard when I open the Antivirus - web browser element. It only allows me to switch off specific websites, Google etc. Firefox is not listed. I will get on to BullGuard to see if they have a solution.

Let us know what happens.

I have been on to my service provider who supply the BullGuard subscription - they cannot help. Can you give me the steps for solution '3' to see if that works?

Gordon_B said

Can you give me the steps for solution '3' to see if that works?

Here's a link to a thread with example steps for #2 and #3: https://support.mozilla.org/questions/1208025

BullGuard pointed me back to solution 1208025. When I change the false to true, the websites open. Having opened several, I then changed the setting back to false as recommended. Alas I am back to the same problem. It would appear that I will have to leave the setting at 'true' for Firefox to work. What risks will this incur?

Some for sure and especially redirects. You could try adding this to Firefox and see if they will work together or create problems : https://addons.mozilla.org/en-US/firefox/addon/trafficlight/ Can get a paid version of Malwarbytes as is meant to be compatible with other A/V programs. It will block bad requests. Also run https://addons.mozilla.org/en-US/firefox/addon/ublock-origin/ Should provide some level if security also.

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

Gordon_B said

What risks will this incur?

Well, trusting everything in the Windows certificate store simply means that any attack on the Windows certificate store by malware installing an untrustworthy signing certificate will affect not just IE, Edge, Chrome, and Opera, but also Firefox. So you lose the sometimes useful feature of Firefox objecting to fake certificates that other browsers trust. I don't know how often that would be useful to you; it has come up from time to time over the years as a way that users discover malware or spyware on their systems.

Somewhere along the line I have lost all my user names and passwords. It still asks me for my master password. Any way of recovering these?

https://support.mozilla.org/kb/Forgot+my+master+password Resetting your master password will remove all of your saved usernames and passwords. This is a security feature.

Type chrome://pippki/content/resetpassword.xul<Enter> in the address bar.

In the event that the passwords information is lost, you should record all information in a separate text file somewhere else on your hard drive, or written down. You can easily copy and paste if you need to do so. If you are concerned about someone else looking at that file, you can compress it using a password.