What is an SSL Certificate Error?
An SSL/TLS Certificate Error occurs when your browser cannot establish an encrypted, verified HTTPS connection to a website. Common warnings include “Your connection is not private” or “NET::ERR_CERT_COMMON_NAME_INVALID”.
Common Causes
- The website’s SSL/TLS certificate has expired
- System clock on your computer is incorrect (causing validity check failures)
- Certificate domain name mismatch
- Public Wi-Fi network attempting to intercept or proxy traffic
How to Fix SSL Warnings
- Check your computer’s date and time — automatic sync fixes over 70% of client-side certificate errors.
- Avoid proceeding on untrusted public Wi-Fi.
- Clear your browser’s SSL state.
- Check website health on IsDownNow to confirm if server administrators are already resolving certificate renewals.