When I log into Yahoo mail on Firefox 40.0.3 (on Windows 7) on my company-supplied laptop, I get this message: "You have asked Firefox to connect securely to us-mg5.mail.… (閱讀更多)
When I log into Yahoo mail on Firefox 40.0.3 (on Windows 7) on my company-supplied laptop, I get this message: "You have asked Firefox to connect securely to us-mg5.mail.yahoo.com, but we can't confirm that your connection is secure."
I cannot create an exception: "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."
The "technical details" section states: "us-mg5.mail.yahoo.com uses an invalid security certificate. The certificate is not trusted because the issuer certificate is unknown. The server might not be sending the appropriate intermediate certificates. An additional root certificate may need to be imported. (Error code: sec_error_unknown_issuer)"
This does not happen at home, so the company laptop has something to do with it, but, even on the company laptop I do not have this problem when using Chrome, so it's not that the company does not allow access to outside mail.
On Firefox, the problem is intermittent. Sometimes, there is no problem and everything works fine. Clearing history/cookies/cache and restarting does not fix the problem. It sometimes goes away on its own for a little while, but then returns.
I have searched every database I could for answers, but have found no solution yet. The computer clock is correct, I'm not using Avast, etc. (some of the other situations I've run across).
I hope that I can get this resolved, because I'd rather keep using FF, which I've used for years, than switch to Chrome.
Thanks for your help, in advance.