Complete Guide to Understanding, Troubleshooting and Fixing SSL Certificate Errors.
An SSL Certificate Error occurs when a web browser cannot establish a secure HTTPS connection with a website. SSL (Secure Sockets Layer) and its successor TLS (Transport Layer Security) encrypt data exchanged between a visitor's browser and the web server, protecting sensitive information such as passwords, payment details, and personal data. When an SSL certificate is invalid, expired, incorrectly installed, or not trusted by the browser, visitors receive security warnings instead of the website.
SSL certificate errors occur when browsers cannot verify the authenticity or validity of the SSL certificate presented by the server.
Check whether your SSL certificate has expired and renew it if necessary.
Ensure the SSL certificate matches your website domain and includes all required subdomains if using a wildcard or multi-domain certificate.
Many SSL issues occur because intermediate certificates are missing, resulting in an incomplete certificate chain.
Redirect all HTTP traffic to HTTPS using your web server configuration or .htaccess file.
RewriteEngine On
RewriteCond %{HTTPS} !=on
RewriteRule ^ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]
Ensure all images, CSS, JavaScript, fonts, and external resources load over HTTPS instead of HTTP.
Incorrect server or system time may cause SSL validation failures.
Confirm your domain correctly points to the server where the SSL certificate is installed.
Restart Apache or Nginx after installing or renewing an SSL certificate.
Use online SSL testing tools to verify certificate installation, chain validation, supported protocols, and encryption strength.
If SSL installation was performed by your hosting provider, contact them to verify certificate installation and server configuration.
| Platform | Possible Cause |
|---|---|
| WordPress | Mixed content, incorrect site URL, plugin conflicts |
| PrestaShop | SSL not enabled correctly, mixed content, configuration issues |
| Laravel | APP_URL configuration, proxy or HTTPS redirect issues |
| Apache | Incorrect VirtualHost SSL configuration |
| Nginx | Certificate path or SSL configuration errors |
The most common causes include expired certificates, incorrect domain names, incomplete certificate chains, mixed content, or server configuration issues.
Some browsers allow visitors to proceed manually, but most users leave the website after seeing a security warning.
Yes. Search engines prefer secure HTTPS websites, and SSL errors can negatively impact user trust, rankings, and conversions.
Most SSL certificates are valid for up to one year. Renew them before they expire or enable automatic renewal if supported.
At SiteFix, we help businesses secure their websites and resolve SSL-related issues quickly and efficiently.
Whether your website displays browser security warnings, HTTPS errors, or certificate validation failures, our experienced developers can diagnose the issue and restore a secure connection with minimal downtime.