How to fix SSL certificate errors
How to Fix SSL Certificate Errors
Few things damage trust faster than a browser warning telling visitors your website “is not secure”.
It doesn’t matter how good your product, design, or content is — once users see an SSL error, many leave immediately.
The good news? Most SSL certificate issues are surprisingly fixable once you understand what’s causing them.
Here’s how to identify the most common HTTPS problems and fix them properly.
What causes SSL certificate errors?
SSL errors appear when a browser cannot properly verify the security of a website.
That can happen for several reasons:
- the certificate expired
- the domain doesn’t match the certificate
- HTTPS is configured incorrectly
- the certificate chain is incomplete
- the server still uses outdated encryption protocols
Modern browsers take SSL validation seriously because HTTPS is responsible for protecting user data and encrypted connections.
Even small configuration mistakes can trigger warnings.
The most common SSL certificate errors
Expired SSL certificate
This is one of the most common issues.
SSL certificates have expiration dates, and once they expire, browsers immediately start showing security warnings.
Typical messages include:
- “Your connection is not private”
- “Certificate has expired”
- “NET::ERR_CERT_DATE_INVALID”
Domain mismatch errors
This happens when the SSL certificate was issued for a different domain than the one being accessed.
For example:
- the certificate covers
example.com - but visitors open
www.example.com
If both versions aren’t included correctly, browsers may reject the certificate.
Mixed content warnings
A website can technically use HTTPS while still loading insecure HTTP resources in the background.
This often includes:
- images
- scripts
- CSS files
- fonts
Browsers may display partial security warnings or remove the secure padlock entirely.
Self-signed certificate errors
Self-signed certificates are not trusted by public browsers because they were not issued by a recognized certificate authority.
They’re acceptable for local development environments — but not for public websites.
Incomplete certificate chain
Sometimes the main certificate is installed correctly, but intermediate certificates are missing.
In that case, browsers cannot fully validate the chain of trust, leading to SSL validation failures on some devices or networks.
How to fix SSL certificate errors
1. Check your certificate status
Before changing anything, inspect the current SSL configuration.
You can use the free SSL Checker by SAVR to verify:
- expiration date
- certificate issuer
- HTTPS configuration
- chain validation
- SSL security problems
A proper scan usually reveals the exact issue within seconds.
2. Renew expired certificates
If the certificate expired, renew it immediately through your hosting provider or certificate authority.
Services like Let's Encrypt often support automatic renewals, which helps prevent future downtime.
After renewal:
- reinstall the certificate if necessary
- restart the web server
- verify HTTPS again
3. Redirect all traffic to HTTPS
Many SSL issues happen because parts of the website still load through HTTP.
Set up permanent 301 redirects so every visitor automatically lands on the HTTPS version of your site.
This also helps:
- avoid duplicate content issues
- improve SEO consistency
- enforce secure connections sitewide
4. Fix mixed content issues
Scan your website for insecure resources still using http://.
Update all internal resources to:
https://- or relative URLs where appropriate
Most modern CMS platforms and CDN providers can help automate this process.
5. Reinstall the full certificate chain
If the chain is incomplete, browsers may trust the certificate inconsistently across devices.
Make sure your server includes:
- the main SSL certificate
- intermediate certificates
- proper CA bundle configuration
This is usually configured directly in:
- Apache
- NGINX
- hosting panels
- CDN dashboards
6. Update outdated TLS protocols
Older protocols like TLS 1.0 and TLS 1.1 are now considered insecure.
Modern websites should support:
- TLS 1.2
- TLS 1.3
Disabling legacy protocols improves both security and browser compatibility.
Why SSL errors hurt more than security
SSL problems don’t just affect encryption.
They also impact:
- SEO performance
- user trust
- conversion rates
- bounce rate
- browser compatibility
- brand credibility
A single browser warning can make even a legitimate business look unsafe.
That’s why regular SSL monitoring matters.
Final thoughts
HTTPS has become part of the basic infrastructure of the modern web.
Most SSL certificate errors are preventable — and usually much easier to fix than website owners expect. The key is identifying problems early before browsers start blocking or warning visitors.
If you want to quickly test your website configuration, you can use the free SSL Certificate Checker by SAVR to detect common SSL issues, certificate errors, and HTTPS misconfigurations in seconds.