hello, first please make sure that the date, time & timezone are set correctly on your system. if this doesn't solve the issue (or it is already set properly), a possible solution depends on different factors:

• what is the error code shown under technical details on the error page?

in case the error code equals sec_error_unknown_issuer, please attempt to add an exception on the bottom of the error page in order to inspect the certificate like it is shown on the screenshot attached:

• which issuer information does the certificate contain?

please report back with those two pieces of information. thank you!

My computer time is correct and is set via our network.

Yes, I get the "sec_error_unknown_issuer" code that I get. I found a page that will let me get the cert, and am enclosing a picture of it.

As you can see, even Mozilla is untrusted.

thank you, this shows that the certificates were issued by an entity named "SAC799VCA01" which is no legit certificate authority and therefore not trusted by firefox and basically performs a man in the middle attack on encrypted connections you try to establish with websites (next to that it generates zero results on google which is strange).

is your pc part of a corporate network? if so, that may be part of a traffic monitoring solution of your employer and you may have to raise this issue with your IT department for them to find a way to include this certificate into firefox properly.

in case this is happening on a private pc, you may have an issue with malware at hand, so please run a full scan of your system with different security tools like the free version of malwarebytes and adwcleaner - Troubleshoot Firefox issues caused by malware