Firefox tells me that facebook and gmail are not secure and won't open them!
"The owner of www.facebook.com has configured their website improperly. To protect your information from being stolen, Firefox has not connected to this website.
This site uses HTTP Strict Transport Security (HSTS) to specify that Firefox only connect to it securely. As a result, it is not possible to add an exception for this certificate."
Alla svar (1)
Are those the only two sites where you've seen a secure connection error?
When you get connection errors for many or most secure sites, the problem usually is one of the following:
(1) Error in your system's date, time, or time zone, which throws off certificate validity checks. Sometimes allowing computers to use an internet-based time source can introduce this problem.
(2) Firefox not being set up to work with your security software that intercepts and filters secure connections. Products with this feature include Avast, BitDefender, Bullguard, ESET / nod32, and Kaspersky; AVG LinkScanner / SurfShield can cause this error on search sites.
If you have any of these products: This support article will walk you through checking for this problem: How to troubleshoot security error codes on secure websites.
(3) Malware on your system intercepting secure connections.
If #1-#2 don't seem relevant, we could assist you in investigating further. Have you saved any certificate "exceptions" while working around this issue?