Certificate is not valid yet

Certificate · Critical severity

What it means

The certificate's start date is in the future. Right now, today, it isn't valid — even though it will be eventually.

Why it matters

Browsers treat a not-yet-valid certificate exactly like an expired one: a hard security warning, no exceptions. Visitors can't reach the site until the start date arrives, or until the underlying problem is fixed.

How to fix it

This is almost always one of two things: a server clock that's set wrong, or a certificate that was issued with the wrong validity period. Check the server's system time first — a clock even a few hours off can trigger this. If the clock is correct, check the certificate's actual "not before" date with the issuing certificate authority and reissue if it's wrong.