62.0.3(62BIT) claims 50% of MY trusted sites r unsafe & won't load, claiming SEC_ERROR_BAD_SIGNATURE...WTH???
My BANK account, my NEWSPAPER account, my food delivery pages.....ALL get the "Problem loading page" and SEC_ERROR_BAD_SIGNATURE message. *I* should have the power to override YOUR decision!!! If this continues, FF will NO LONGER be my default browser! PLEASE stop fixing what ain't broke!
Opaite Mbohovái (2)
There is security software like Avast, Kaspersky, BitDefender and ESET that intercept secure connection certificates and send their own.
https://support.mozilla.org/en-US/kb/firefox-cant-load-websites-other-browsers-can
https://support.mozilla.org/en-US/kb/firefox-and-other-browsers-cant-load-websites
https://support.mozilla.org/en-US/kb/secure-connection-failed-error-message
https://support.mozilla.org/en-US/kb/connection-untrusted-error-message
Adding onto what FredMcD said above, you may also want to explore the What do the security warning codes mean? article, which also has a lot of information on why you may not be able to access a website.