Ensuring your website runs smoothly and safely starts with dealing firmly with SSL/TLS issues. A security certificate error not only scares away visitors but also damages your brand trust and search engine ranking.
With cyber-threats rising and HTTPS now expected, you cannot ignore these problems. In this article you’ll learn how to diagnose certificate problems, fix them step-by-step, prevent future errors, and optimize for performance and trust at the same time.
Understanding Website Security Certificate Issues
A website security certificate (often called SSL or TLS certificate) is the anchor of trust between your server and your visitor’s browser. If any link in that chain falters, browsers will show warnings like “Not Secure” or “There is a problem with this website’s security certificate.”
Several common root causes trigger these warnings:
- The certificate has expired or is not yet active.
- The certificate domain name (Common Name or SAN) doesn’t match the website address.
- Intermediate certificates are missing, breaking the trust chain.
- Mixed content (HTTP resources on an HTTPS page) undermines the secure connection.
- The visitor’s system clock is wrong, making a valid certificate appear invalid.
- A browser, plugin, or server misconfiguration prevents proper certificate handshake.
Because of these issues, a simple expired certificate can cause big trouble. According to a 2024 report, over 90% of organizations deployed more certificates than ever while only about one-third used dedicated lifecycle tools.
Why Fixing Certificate Errors Matters
Fixing these certificate issues is not optional; it’s necessary for several key reasons:
- User trust & experience: Browsers flag “Not Secure” sites, prompting many users to leave immediately.
- SEO and visibility: Search engines now favor HTTPS; insecure sites may rank lower.
- Data protection and compliance: If you handle user data (emails, payments), you must encrypt it. Certificates help you meet that requirement.
- Brand reputation: A certificate error screams amateur or unsafe site; fixing it elevates your professionalism.
- Performance: HTTPS opens the door to HTTP/2, improved caching, and better mobile experiences.
With those stakes clear, let’s roll up our sleeves.
Step-By-Step Process to Fix Website Security Certificate Problems
1. Identify the issue precisely
First, ascertain what kind of certificate error you’re dealing with.
- Load your website in a browser; click the padlock or warning icon to view the certificate details, chain, and error message.
- Use online tools to confirm expiry dates, missing intermediates, and mismatches.
- Check your domain, subdomains, and alias names; the certificate must list them all.
- Test for mixed content: open browser developer console → Network tab → look for HTTP items on an HTTPS page.
- Ensure your server clock and visitor devices are synchronized (especially if a certificate appears “not yet valid”).
2. Renew or replace the certificate
If expiry or mis-issuance is the problem, you need to take action:
- Generate a fresh Certificate Signing Request (CSR) via your hosting panel or server.
- Select the correct certificate type (Domain Validated, Organization Validated, Extended Validation, or Wildcard) depending on your site’s needs.
- Submit the CSR to a recognized Certificate Authority and pass any required validation (email, DNS record, file upload).
- When you receive the certificate bundle (leaf and intermediates), download and prepare it for installation.
3. Install and configure the certificate on your server
Proper installation prevents a lot of downstream errors:
- Upload the certificate files to your server; in some hosting environments this is automatic.
- Configure your web server (Apache, Nginx, IIS, etc.) to use the new certificate, bind it to the correct port (443), and ensure the intermediate chain is applied.
- Configure HTTP to HTTPS redirects so all traffic uses the secure version.
- Update your HSTS (HTTP Strict Transport Security) header if you want to enforce HTTPS.
- Check for mixed content on your pages and fix all links pointing to “http://” so they reference “https://”.
4. Test and verify end-to-end
After installation, you must verify everything works correctly:
- Visit the website via HTTPS, ensure the padlock icon appears with no warnings, and verify domain, issuer, and expiry details.
- Use an SSL checker tool to scan for chain issues, expired intermediates, unsupported ciphers, or protocols.
- Check that both “www” and non-www domains resolve and redirect properly.
- Clear browser cache, check system clock, and test on mobile and desktop.
- Confirm there are no mixed content warnings in the developer console.
- Submit your HTTPS version in Google Search Console or similar tools to update indexing.
5. Prevent future certificate errors
Fixing a certificate problem is one thing; keeping it fixed is another. Here are best practices:
- Maintain a certificate inventory listing domains, subdomains, issuing authority, expiry date, and server location.
- Set alerts for certificate expiry: many tools can notify you 30, 14, and 7 days in advance.
- Automate renewal where possible using Let’s Encrypt or other ACME-compatible services.
- Review and remove certificates for decommissioned servers or domains.
- Periodically test your site for mixed content, outdated protocols, and weak ciphers.
- Update your server software, CMS, plugins, and themes regularly so compatibility remains high and vulnerabilities stay low.
Common Errors and Specific Fixes
Expired certificate
Solution: Renew immediately, install the new certificate, and verify the chain. Browsers check both leaf and intermediate certificates for validity.
Domain name mismatch
If your certificate lists secure.example.com and a user visits www.example.com, the mismatch shows. Solution: Obtain a certificate matching all required names (SAN or wildcard) and re-install.
Missing intermediate certificates
The browser cannot complete the trust chain if intermediates aren’t presented. Solution: Include the full certificate bundle and test with chain-check tools.
Mixed content warnings
A secure page loads insecure resources. Solution: Convert all resources (images, scripts, CSS) to HTTPS, update hard-coded URLs, and use relative paths.
Incorrect system clock
If the client’s date/time is wrong, valid certificates might appear expired or not yet valid. Solution: Sync the system clock or replace the CMOS battery and test again.
Outdated protocols or ciphers
Modern browsers reject connections if the server uses deprecated TLS versions (1.0/1.1) or weak ciphers. Solution: Configure the server for TLS 1.2 or higher (preferably TLS 1.3) and remove obsolete cipher suites.
Why “Not Secure” Still Appears After Installation
Sometimes you install an SSL certificate and think the job is done — yet visitors still see “Not Secure.” Here’s why:
- You forgot to redirect all HTTP traffic, so the site still loads insecurely.
- Internal links, images, or resources still use “http://”.
- The HTTPS version is not verified in search tools.
- The browser or caching proxy still holds old certificate data.
- A subdomain or alias is not covered by the certificate.
SEO and Business Benefits of a Flawless Certificate Setup
- HTTPS is a ranking signal and improves visibility. A secure website gains trust and traffic.
- You reduce bounce rates because visitors trust the padlock symbol and stay longer.
- You build brand integrity — especially crucial for e-commerce or any platform handling sensitive data.
- You unlock advanced web technologies like HTTP/2 and better performance.
- You prevent compliance or legal issues related to unsecured data transmission.
Conclusion
In over 30 years of advising businesses on web security, I’ve seen one truth repeat: ignoring certificate warnings always costs more than fixing them early.
By diagnosing your SSL issue, renewing and installing certificates correctly, verifying your setup, and automating renewals, you’ll protect your visitors, strengthen SEO, and elevate your brand credibility. Every trusted site begins with a valid certificate — make yours one of them.