hello toniwalker10, first please make sure that the date, time & timezone are set correctly on your system. if this doesn't solve the issue (or it is already set properly), a possible solution depends on different factors:

• what is the error code shown under technical details on the error page?

in case the error code equals sec_error_unknown_issuer, please attempt to add an exception on the bottom of the error page (don't add it for real) & inspect the certificate. see the screenshot attached for instructions:

• which issuer information does the certificate contain in your case?

thank you!

Thank you for the reply. There is no option for I understand the risks. The exception I added via the firefox options tab. There is no error code this is all it shows (Error code: sec_error_unknown_issuer) Date and time is set correctly I can access Yahoo on Chrome so why not on FF? I just want to option to jgo to the site not be blocked by FF when it is my computer. Maybe I should uninstall FF and keep on Chrome.

Would be grateful for a reply. Why am I getting this with FF and not other browsers? Also why can FF NOT give a choice on whether to go to the site instead of blocking the way? It is my computer and not FF's

Try to rename the cert8.db file (cert8.db.old) and delete the cert_override.txt file in the Firefox profile folder to remove intermediate certificates and exceptions that Firefox has stored.

If that has helped to solve the problem then you can remove the renamed cert8.db.old file. Otherwise you can rename (or copy) the cert8.db.old file to cert8.db to restore the previously stored intermediate certificates. Firefox will automatically store intermediate certificates when you visit websites that send such a certificate.

You can use this button to go to the currently used Firefox profile folder:

• Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder)
• http://kb.mozillazine.org/Profile_folder_-_Firefox

You can retrieve the certificate and check details like who issued certificates and expiration dates of certificates.

• Click the link at the bottom of the error page: "I Understand the Risks"

Let Firefox retrieve the certificate: "Add Exception" -> "Get Certificate".

• Click the "View..." button and inspect the certificate and check who is the issuer of the certificate.

You can see more Details like intermediate certificates that are used in the Details pane.

If "I Understand the Risks" is missing then this page may be opened in an (i)frame and in that case try the right-click context menu and use "This Frame: Open Frame in New Tab".

Nothing you have suggested has worked. The issue has got to lie with Firefox and not me or Yahoo. I don't think the browser should stop me from going to a major search engine. It is up to me to decide on that issue. Yahoo is the only search engine I can use because google is blocked where I live and the other search engines are useless. Maybe your boys should check with Yahoo about the use of certificates and incorporate the findings into Firefox.

Did you check who is the issuer of the certificate like posted above?

Can you attach a screenshot that shows the window that open if you click View Certificate and possibly also a screenshot of the Details pane with the Issuer selected, so it shows the issuer details in the bottom pane?

• http://en.wikipedia.org/wiki/Screenshot
• https://support.mozilla.org/kb/how-do-i-create-screenshot-my-problem

• Use a compressed image type like PNG or JPG to save the screenshot
• Make sure that you do not exceed the maximum size of 1 MB

Can't do a screen shot so have copied and pasted the text. Imagine this as an image.

This Connection is Untrusted

You have asked Firefox to connect securely to uk.yahoo.com, but we can't confirm that your connection is secure.

Normally, when you try to connect securely, sites will present trusted identification to prove that you are going to the right place. However, this site's identity can't be verified. What Should I Do?

If you usually connect to this site without problems, this error could mean that someone is trying to impersonate the site, and you shouldn't continue.

uk.yahoo.com uses an invalid security certificate. The certificate is not trusted because it is self-signed. The certificate is only valid for yahoo.com (Error code: sec_error_unknown_issuer)

This is one for https:// www.yahoo.com

This Connection is Untrusted

You have asked Firefox to connect securely to www.yahoo.com, but we can't confirm that your connection is secure.

Normally, when you try to connect securely, sites will present trusted identification to prove that you are going to the right place. However, this site's identity can't be verified. What Should I Do?

If you usually connect to this site without problems, this error could mean that someone is trying to impersonate the site, and you shouldn't continue.

www.yahoo.com uses an invalid security certificate. The certificate is not trusted because it is self-signed. The certificate is only valid for yahoo.com (Error code: sec_error_unknown_issuer)

Try to rename the cert8.db file (cert8.db.old) and delete the cert_override.txt file in the Firefox profile folder to remove intermediate certificates and exceptions that Firefox has stored.

If that has helped to solve the problem then you can remove the renamed cert8.db.old file. Otherwise you can rename (or copy) the cert8.db.old file to cert8.db to restore the previously stored intermediate certificates. Firefox will automatically store intermediate certificates when you visit websites that send such a certificate.

If that didn't help then remove or rename secmod.db (secmod.db.old) as well.

You can use this button to go to the currently used Firefox profile folder:

• Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder)
• http://kb.mozillazine.org/Profile_folder_-_Firefox