Why Apache WordPress Show Not Trusted Certificate – Complete Guide

If you’ve visited your WordPress site on an Apache server recently and seen a warning “Not Trusted Certificate” you’re not alone. This means your SSL/TLS certificate is either misconfigured or not recognized by the browser and will scare off visitors and hurt your site’s credibility. For businesses that rely on online presence, e-commerce stores or blogs with a large audience you need to fix this ASAP.

In this guide we’ll go deep into why Apache WordPress show Not Trusted Certificate, how to diagnose the problem and step by step solutions to fix it. Whether you’re a small business owner, developer or website admin, this guide will give you actionable knowledge to secure your site, restore user trust and improve your search engine rankings.

By the end of this article, you’ll understand:

• The main reasons for untrusted SSL certificates on Apache-hosted WordPress sites.
• How to diagnose and troubleshoot SSL issues efficiently.
• Preventive strategies to avoid recurring SSL errors.
• Advanced troubleshooting tips and real-world examples for reference.

What is SSL/TLS?

SSL (Secure Sockets Layer) and its newer cousin TLS (Transport Layer Security) are the cryptographic protocols that make sure communication between your visitor’s browser and your website is secure. When set up correctly, SSL encrypts sensitive info like passwords, credit card numbers and personal data so hackers can’t intercept it. This is the foundation of trust with your visitors.

Why SSL Matters for WordPress on Apache

WordPress sites handle personal data, e-commerce transactions and membership details. Running WordPress on Apache without a trusted SSL certificate exposes your users to attacks and browser warnings like “Not Trusted Certificate”. Some key reasons SSL is indispensable:

1. Data Encryption: Protects sensitive user data in transit.
2. Authentication: Confirms your website’s identity to browsers, preventing impersonation attacks.
3. SEO Advantage: Google favors HTTPS sites in search rankings.
4. User Trust: Secure websites display the padlock symbol in browsers, reassuring visitors.

How SSL Works: The Basics

When a user accesses your WordPress site via HTTPS, the following occurs:

1. The browser requests your website’s SSL certificate.
2. The browser verifies the certificate against trusted Certificate Authorities (CAs).
3. If the certificate is valid, a secure encrypted connection is established.
4. If the certificate is missing, invalid, or misconfigured, the browser shows a warning like “Not Trusted Certificate”.

Pro Tip: Even if your SSL certificate is installed, missing intermediate certificates or mismatched domain names can still trigger warnings.

Understanding the root cause is the first step to resolution. Let’s break down why Apache WordPress shows “Not Trusted Certificate”:

1. Self-Signed Certificates

Some developers generate self signed SSL certificates for testing purposes. While they work for encryption, browsers don’t trust self signed certificates by default. Users see warnings and won’t go to your site.

2. Expired Certificates

Every SSL certificate has a validity period, 90 days (for free certificates like Let’s Encrypt) to several years (for commercial certificates). If your certificate expires, browsers flag it as untrusted immediately.

3. Mismatched Domain Names

SSL certificates are issued for specific domain names. If your WordPress site is accessed via www.example.com but your certificate is for example.com, browsers will flag the mismatch and show “Not Trusted Certificate”.

4. Missing Intermediate Certificates

Intermediate certificates connect your site’s SSL certificate to a trusted root certificate authority. If they’re missing or misconfigured in Apache, browsers can’t verify the certificate chain.

5. Incorrect Apache Configuration

Misconfigured Apache settings, such as wrong certificate paths or missing directives in ssl.conf or httpd.conf, can prevent proper SSL handshake. Common issues include:

• Using outdated SSLCertificateFile paths.
• Not including SSLCertificateChainFile for intermediates.
• Conflicting virtual host configurations for HTTPS.

6. WordPress Configuration Issues

Even with correct Apache SSL settings, WordPress settings can override your HTTPS setup:

• WordPress Address (URL) and Site Address (URL) in settings must start with https://.
• Plugins that force HTTP or rewrite URLs incorrectly may trigger certificate warnings.

Before attempting fixes, it’s crucial to diagnose why Apache WordPress show Not Trusted Certificate. A systematic approach ensures you address the root cause rather than applying a temporary patch.

Step 1: Browser Inspection

Use your browser’s developer tools or SSL warning details to understand the problem:

• Click the padlock or warning symbol.
• Look for messages like:
  • “Certificate expired”
  • “Self-signed certificate”
  • “Certificate does not match the domain”
• Note the issuing authority and certificate validity dates.

Step 2: Online SSL Testing Tools

Tools like SSL Labs’ SSL Test or Why No Padlock provide detailed analysis:

• Check the certificate chain.
• Identify missing intermediates.
• Detects unsupported encryption algorithms.
• Validate browser trust across platforms.

Step 3: Apache SSL Configuration Check

SSH into your server and examine Apache’s SSL configuration files (usually ssl.conf, httpd.conf, or virtual host files):

Confirm the certificate path:

SSLCertificateFile /etc/ssl/certs/example.com.crt

SSLCertificateKeyFile /etc/ssl/private/example.com.key

SSLCertificateChainFile /etc/ssl/certs/intermediate.crt

Check for syntax errors:

apachectl configtest

Reload Apache to apply changes:

systemctl reload apache2

Step 4: WordPress Configuration Validation

• Ensure both WordPress Address (URL) and Site Address (URL) are set to https://.

Inspect .htaccess rules for HTTPS redirects:

RewriteEngine On

RewriteCond %{HTTPS} !=on

RewriteRule ^ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]

• Disable conflicting plugins temporarily to isolate SSL-related issues.

Pro Tip: Keep a backup of .htaccess and configuration files before making changes.

Now that you’ve diagnosed the root cause, it’s time to fix the SSL issue properly. Follow these expert steps:

Step 1: Obtain a Trusted SSL Certificate

• Free Option: Let’s Encrypt provides valid certificates with automatic renewal.
• Paid Option: Use providers like DigiCert, Sectigo, or GoDaddy for extended validation and warranty.
• Ensure the certificate matches your primary domain (www.example.com vs example.com).

Step 2: Install Certificate in Apache

Place the certificate and private key in secure directories:

/etc/ssl/certs/example.com.crt

/etc/ssl/private/example.com.key

• Include intermediate certificates in SSLCertificateChainFile or combine with your main certificate depending on Apache version.

Step 3: Update Apache Virtual Host

Edit your HTTPS virtual host:

<VirtualHost *:443>

    ServerName example.com

    DocumentRoot /var/www/html

    SSLEngine on

    SSLCertificateFile /etc/ssl/certs/example.com.crt

    SSLCertificateKeyFile /etc/ssl/private/example.com.key

    SSLCertificateChainFile /etc/ssl/certs/intermediate.crt

    <Directory /var/www/html>

        AllowOverride All

    </Directory>

</VirtualHost>

Save and reload Apache:

systemctl reload apache2

Step 4: Enforce HTTPS in WordPress

• Update WordPress Address (URL) and Site Address (URL) to https://.
• Add redirect rules in .htaccess for automatic HTTP → HTTPS forwarding.
• Use plugins like Really Simple SSL for safer migration if needed.

Step 5: Test Your Configuration

• Clear browser cache and revisit your site.
• Use SSL testing tools to confirm:
  • Full trust chain
  • Valid expiration
  • Correct domain coverage
• Ensure all assets (images, scripts) load over HTTPS to avoid mixed content warnings.

Step 6: Automate SSL Renewal

For Let’s Encrypt:

certbot renew –dry-run

• Set up cron jobs to auto-renew and reload Apache, preventing future “Not Trusted Certificate” errors.

Step 7: Redirect HTTP to HTTPS

To ensure all traffic is secure:

Add this snippet to your Apache configuration or .htaccess file:

RewriteEngine On
RewriteCond %{HTTPS} off
RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]

Preventing SSL issues is always better than troubleshooting them. Here’s a practical approach to ensure your Apache WordPress site remains secure and trusted:

Keep Your Certificates Updated

• Always monitor expiration dates.
• Enable automated renewal for Let’s Encrypt certificates.
• Avoid using self-signed certificates for production sites; they trigger trust warnings in all major browsers.

Use Reputable Certificate Authorities

• Choose well-known CAs like DigiCert, Sectigo, or GoDaddy.
• Avoid obscure or free CAs for mission-critical sites that require extended validation (EV) certificates.
• Ensure your certificate covers all variants: www.example.com, example.com, and subdomains if needed.

Configure Apache Correctly

• Always specify the SSLCertificateChainFile (or combine intermediate certificates in Apache 2.4.8+).

Use secure protocols and ciphers:

SSLProtocol all -SSLv2 -SSLv3

SSLCipherSuite HIGH:!aNULL:!MD5

• Regularly run apachectl configtest after making SSL or Apache changes.

Enforce HTTPS Across Your Site

• Implement HTTP → HTTPS redirects in .htaccess.
• Ensure WordPress URLs use HTTPS in Settings → General.
• Fix mixed content by updating internal links, scripts, and images to HTTPS.

Monitor SSL Health

• Use monitoring tools like SSL Labs, Site24x7, or UptimeRobot.
• Set alerts for certificate expiry or trust chain issues.
• Regularly audit Apache logs for SSL/TLS warnings.

Pro Tip: Maintaining proactive SSL health checks prevents sudden browser trust warnings that impact traffic and SEO.

Even after following standard procedures, some sites may still show “Not Trusted Certificate.” Here’s how to handle advanced scenarios:

Mixed Content Errors

• Browsers may flag certificates as untrusted if some assets load via HTTP.
• Inspect the browser console and update asset URLs.
• Use a plugin like Better Search Replace or WordPress functions to bulk update URLs.

Wrong Domain on Certificate

• Ensure your SSL certificate matches the domain exactly.
• If you have multiple domains or subdomains, use SAN (Subject Alternative Name) certificates or wildcard SSL.

Browser or OS Trust Issues

• Some old browsers or OS versions may not recognize new CAs.
• Check compatibility with Can I Use SSL databases.
• Encourage users to update browsers for proper trust.

Server-Side Caching & Proxy Issues

• Reverse proxies or CDNs can sometimes serve outdated certificates.
• Clear cache and reload Apache after SSL updates.
• Verify CDN SSL settings match your origin server.

Check for Conflicting Plugins

• Security or SSL plugins can override or misconfigure certificates.
• Temporarily deactivate SSL-related plugins and test.
• Reconfigure plugins to align with your Apache SSL setup.

Re-issue Certificates if Needed

• If trust warnings persist despite proper installation, re-issue the certificate from your CA.
• Validate the full chain before re-deploying.

Addressing why Apache WordPress show Not Trusted Certificate requires a systematic approach: diagnose the issue, correct configuration, and maintain proactive SSL practices. By having valid certificates, correct Apache setup and WordPress URLs consistently HTTPS you can prevent trust errors that affect users and SEO.

Remember, SSL’s are not just a technical requirement but a foundation of your site’s credibility and success. Don’t wait, act now and keep your WordPress site safe and trusted!

1. Can I Use a Self-Signed Certificate for My WordPress Site?

You can technically use a self signed SSL but most browsers will flag it as “Not Trusted” and warn visitors your site may be unsafe. This can lose trust and deter users from interacting with your site. For any public facing WordPress site you should use an SSL issued by a recognized Certificate Authority (CA) for proper security and credibility.

2. What Happens If I Ignore the SSL Warning?

Leaving SSL issues unresolved will trigger “Not Trusted Certificate” alerts in browsers and drive visitors away immediately. Beyond user trust, search engines like Google may lower your SEO ranking. In short, ignoring SSL warnings can cost you traffic, conversions and overall credibility with your audience.

3. Are Free SSL Certificates Secure Enough?

Yes. Free SSLs like Let’s Encrypt offer strong encryption and are trusted by all browsers. They are the same as most paid SSLs. Paid SSLs offer extras like extended validation (EV), warranties or brand credibility – useful for professional or enterprise sites.

4. How Often Should I Renew My SSL Certificate?

Renewal is important to avoid “Not Trusted Certificate” errors. Free certificates like Let’s Encrypt expire every 90 days and rely on automated renewal. Paid certificates last 1-2 years. Always renew on time to keep your connections secure and your visitors trusting you.