How to Fix SSL Certificate Errors on Your Website

An SSL certificate error is one of the fastest ways to lose visitor trust — browsers show a big red warning before anyone even reaches your site. The good news is that most SSL issues fall into a handful of common categories, and each has a straightforward fix.

1. Expired Certificate

SSL certificates aren't permanent — most last 90 days to a year. If yours has expired, your certificate authority (or hosting provider, if they manage it automatically) needs to reissue it. Services like Let's Encrypt can auto-renew certificates every 90 days if configured correctly, which removes this problem entirely.

2. Domain Mismatch

This happens when the certificate was issued for a different domain than the one being accessed — commonly seen when a certificate covers 'example.com' but not 'www.example.com', or vice versa. The fix is to issue a certificate that covers both, or configure a proper redirect between the two.

3. Mixed Content Warnings

Even with a valid certificate, if your page loads some resources (images, scripts, stylesheets) over plain HTTP instead of HTTPS, browsers will flag it as insecure. Search your codebase for hardcoded 'http://' links and switch them to 'https://' or protocol-relative URLs.

4. Incomplete Certificate Chain

Your server needs to present not just its own certificate, but the intermediate certificates that link it back to a trusted root authority. Missing intermediates cause errors on some devices/browsers even though the cert looks fine on others. Most hosting panels have a straightforward way to install the full chain — check your certificate authority's documentation for the correct bundle.

How to Check Your Site

Run your domain through Nexora Shield's SSL Checker to instantly see your certificate's issuer, validity period, and TLS version — and catch these issues before your visitors do.