Sorry for the inconvenience. It sounds as though you are getting this error page:

What do the security warning codes mean?

If you click the "Advanced" button on that page, you can view more detailed technical information about the problem, including a SEC_ERROR_CODE. This article covers the code users most commonly report after a significant change to their Firefox settings such as a Refresh:

How to troubleshoot security error codes on secure websites

Does that help you identify an explanation and solution?

I do not know how this problem began nor do I understand from any of the "troubleshooting" how to fix it. I have no idea what an AVAST is nor do I intend to reinstall anything. I intend to dump firefox unless you or someone can walk me through how to fivx the problem. I have all my important accounts online and cannot access ANY of them UGH! Is the a way to TALK to someone? What a concept!!! PHONE? HELP?

Hi MrsBurnett, let me start by saying that Windows 10 comes with the Edge browser, so if you need to get online urgently, you can use Edge. If you need to transfer your Firefox bookmarks to Edge, you can export them to a file, then open that file in Edge. See:

Export Firefox bookmarks to an HTML file to back up or transfer bookmarks

Now, back to Firefox:

I have no idea what an AVAST is nor do I intend to reinstall anything.

Do you use Avast security software? If you are not familiar with that program, most likely that is not the issue. Did you recognize the names of other programs mentioned in the article:

• Bitdefender
• Bullguard
• ESET
• Kaspersky
• Microsoft Family Safety

When you click the Advanced button on the error page, if you have the SEC_ERROR_UNKNOWN_ISSUER code, you can click that code to display a coded version of the certificate Firefox doesn't trust. Click the button to copy the certificate, then paste it into a reply. A volunteer can decode it and let you know whether it identifies the source of the problem.

You can click the "Advanced" button to expand this section and show extra details. If the certificate is not trusted because no issuer chain was provided (SEC_ERROR_UNKNOWN_ISSUER) then click the blue error message to expand this section and show the certificate chain. You can click "Copy text to clipboard" and paste this base64 encoded certificate chain text in a reply. That will allow us to details like the issuer of the certificate.

• always be cautious when you get an 'Untrusted' error message
• never create a permanent exception without investigating the cause and only use this to inspect the certificate

You can remove all data stored in Firefox from a specific domain via "Forget About This Site" in the right-click context menu of an history entry ("History -> Show All History" or "View -> Sidebar -> History").

Using "Forget About This Site" will remove all data stored in Firefox from that domain like bookmarks and history and cookies and passwords and cache and exceptions, so be cautious. If you have a password or other data from that domain that you do not want to lose then make sure to backup this data or make a note.

You can't recover from this 'forget' unless you have a backup of involved files.

If you revisit a 'forgotten' website then data from that website will be saved once again.

• https://support.mozilla.org/en-US/kb/delete-browsing-search-download-history-firefox

A less likely cause for secure connections issue in this case however make sure your system date is correct on Windows 10.