hello, when you click on "technical details" on the error page, which error code is shown? & which security software are you using?

The error code is "sec_error_unknown_issuer."

As far as security software goes, I'm not sure. This is a work computer.

If possible then you should also update to the latest Firefox 10.0.5 ESR version.

• Firefox 10.0.x ESR: http://www.mozilla.org/en-US/firefox/organizations/all.html

It is best not to add an exception for common sites that should work, but try to investigate what is wrong.

Do you only see that error with the Gmail site?

Try to rename the cert8.db file in the Firefox profile folder to cert8.db.old or delete the cert8.db file to remove intermediate certificates that Firefox has stored.

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

• Help > Troubleshooting Information > Profile Directory: Open Containing Folder
• http://kb.mozillazine.org/Profile_folder_-_Firefox

So far, the only site I've accessed with that problem is Google/GMail. Any site requiring a Google Login, it appears.

I tried renaming cert8.db to cert8.db.old and it didn't work.

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.

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

maybe you can also take a screenshot of the certificate details and attach it to your next post. we might get some clues out of it, what's going on...

Here are my screenshots:

http://i.imgur.com/aytEq.png

I clicked "add exception" and got the window here:

http://i.imgur.com/k3AU9.png

Then, I clicked on confirm, and it went right back to the untrusted connection window.

the interesting part would be when you click on "view" on the "add exception" page. thank you...

Sorry, I'm out of it today...here it is:

http://i.imgur.com/ykfrM.png

ok, this looks like your employer is somehow hooking in to/monitoring secure traffic. probably contact your it department in order to sort this thing out...

I get a certificate issued by Thawte SGC CA that has the same validity range.

Check the connection settings.

• Tools > Options > Advanced : Network : Connection > Settings
• https://support.mozilla.org/kb/Options+window+-+Advanced+panel

If you do not need to use a proxy to connect to internet then select "No Proxy" if the default "Use the system proxy settings" setting doesn't work.

See "Firefox connection settings":

• https://support.mozilla.org/kb/Firefox+cannot+load+websites+but+other+programs+can

--- Do a malware check with some malware scanning programs on the Windows computer.
You need to scan with all programs because each program detects different malware.
Make sure that you update each program to get the latest version of their databases before doing a scan.

• http://www.malwarebytes.org/mbam.php - Malwarebytes' Anti-Malware
• http://www.superantispyware.com/ - SuperAntispyware
• http://www.microsoft.com/security/scanner/en-us/default.aspx - Microsoft Safety Scanner
• http://www.microsoft.com/windows/products/winfamily/defender/default.mspx - Windows Defender: Home Page
• http://www.safer-networking.org/en/index.html - Spybot Search & Destroy

You can also do a check for a rootkit infection with TDSSKiller.

• http://support.kaspersky.com/viruses/solutions?qid=208280684

See also:

• "Spyware on Windows": http://kb.mozillazine.org/Popups_not_blocked