Browser SSL Certificate Errors — NET::ERR_CERT Errors Explained

Comprehensive guide to browser SSL certificate errors including ERR_CERT_AUTHORITY_INVALID, ERR_CERT_DATE_INVALID, ERR_CERT_COMMON_NAME_INVALID, and HSTS errors. This guide covers everything you need to know about this topic, including common causes, step-by-step solutions, and answers to frequently asked questions.

Here are the key things to understand: SSL certificate errors prevent the browser from establishing a secure HTTPS connection. ERR_CERT_AUTHORITY_INVALID: the certificate issuer is not trusted by the browser. ERR_CERT_DATE_INVALID: the certificate has expired or is not yet valid. ERR_CERT_COMMON_NAME_INVALID: the domain name does not match the certificate. HSTS errors (NET::ERR_CERT_AUTHORITY_INVALID on HSTS sites) cannot be bypassed. Understanding these fundamentals will help you diagnose and resolve this issue more effectively.

The most common reasons this occurs include: Certificate expired — SSL certificates must be renewed periodically (90 days for Let's Encrypt, 1 year for commercial). Self-signed certificate not trusted by the browser's certificate store. Domain name mismatch: certificate issued for www.example.com but accessed via example.com. System clock wrong: if the computer's date/time is incorrect, valid certificates appear expired. Corporate SSL inspection (proxy re-signs certificates) causing authority trust issues. Identifying the root cause is the first step toward finding the right solution.

To resolve this, follow these recommended steps: Check the system clock: incorrect date/time causes valid certificates to appear expired. Click the lock/warning icon in the URL bar > Certificate to see certificate details and expiry. For AUTHORITY_INVALID: the site administrator needs to install the correct certificate or fix the chain. For DATE_INVALID: the site administrator needs to renew the expired certificate. For COMMON_NAME_INVALID: ensure the URL matches the certificate's domain (www vs non-www). Corporate proxy: install the organization's root certificate in your browser/OS trusted store. If these steps do not resolve the issue, consider consulting additional resources or a qualified professional.

This article is part of our Browser Errors collection on Error Codes Wiki. We provide comprehensive, up-to-date information to help you find solutions quickly.