Firefox brings up "this connection is untrusted" when signing into my email. 'add exception" no luck?

[Janet]

the add exception only works for the current sign in. The same thing happens again next time I sign in. Here is what I get after signing in. <https://ca.mg5.mail.yahoo.com/neo/launch?.rand=a800k4biqs0fq>

[Sam]

Seeing the alert does not necessarily mean that the website you're visiting is trying to trick you into believing it is a different website - it means that Firefox isn't able to verify the identity of the website, and that you should proceed carefully.

The safest thing to do is to click Get me out of here!, or to go to a different website. Unless you know and understand the technical reason why the website presented incorrect identification, and are willing to risk communicating over a connection that could be vulnerable to an eavesdropper, you should not proceed to the website.

If possible, you should contact the owners of the website and inform them of the error.

You should only bypass the warning if you're confident in both the identity of the website and the integrity of your connection - even if you trust the site, someone could be tampering with your connection. Legitimate public sites will not ask you to add connection rule exceptions - an invalid certificate can be an indication of a web page that will defraud you or steal your identity.

On the warning page, click I Understand the Risks.
Click Add Exception.... The Add Security Exception dialog will appear.
Read the text describing the problems with this site.
Click Confirm Security Exception if you want to trust the site.

Try using Firefox in safe mode.

-https://support.mozilla.org/en-US/kb/connection-untrusted-error-message