How to Fix SSL Certificate Errors on a Website: Complete HTTPS Security Guide
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Publisher ID: ca-pub-XXXXXXXXXXXXXXXX (Configured in config.php)When web browsers encounter an invalid, expired, or mismatched SSL/TLS certificate, they display warnings like "Your connection is not private". Learn how to renew certificates, fix domain mismatches, resolve mixed content warnings, and enforce HTTPS redirects.
Verify whether the certificate has expired or covers both your www and non-www domain variations. Re-install or renew your free Let's Encrypt SSL certificate in your hosting control panel. To fix yellow padlock "Mixed Content" warnings, ensure all images and stylesheets load via https:// instead of http://.
📋 Guide Table of Contents
1. Problem Diagnosis & Symptoms
Modern browsers flag non-HTTPS websites as "Not Secure" and block access with security interstitials when certificates fail.
2. Primary Root Causes
- Cause: The SSL certificate expired before automatic renewal was completed.
- Cause: Mixed content loading via insecure http://.
3. Step-by-Step Diagnostic Fixes
Force HTTPS Cleanly in .htaccess
Redirect all HTTP requests to HTTPS.
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteCond %{HTTPS} off
RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]
</IfModule>4. How to Verify the Resolution
- Check padlock icon in browser to ensure secure status.
5. Diagnostic Troubleshooting Matrix
| Symptom Observed | Root Cause | Recommended Action |
|---|---|---|
| ERR_TOO_MANY_REDIRECTS | Cloudflare Flexible SSL conflicting with server HTTPS redirect | Change Cloudflare SSL mode to Full (Strict) |
6. Critical Mistakes to Avoid
- ❌ Never ignore mixed content warnings.
7. Frequently Asked Questions
❓ Does Let's Encrypt renew automatically?
Yes, hosting providers usually run a cron job to renew Let's Encrypt every 60-90 days.
Official Technical References
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