Dealing with SSL handshake errors can be frustrating, especially when you’re trying to run a reliable WordPress site hosted on IONOS. These issues might occur suddenly or persist after a migration, SSL certificate update, or plugin installation. Understanding the cause and fixing it promptly is crucial for site availability, security, and user trust.
TL;DR
If you’re encountering SSL handshake errors between your WordPress site and IONOS hosting, the issue likely stems from misconfigured SSL certificates, outdated cURL dependencies, or plugin conflicts. Fixes include reinstalling SSL certificates from IONOS, checking WordPress URLs, updating PHP and cURL, or configuring Cloudflare (if in use). Follow our step-by-step troubleshooting methods to quickly resolve the error and get your website running smoothly again.
What Is an SSL Handshake Error?
An SSL handshake error occurs when the browser fails to establish a secure connection with the server. SSL (Secure Sockets Layer) is critical for encrypting data between your site and the users’ browsers. During the handshake, several things are verified — the SSL certificate’s validity, browser and server compatibility, and more.
If you’re using IONOS as your hosting provider and you manage your site with WordPress, any mismatch in SSL setups, expired certificates, or incompatible configurations can cause these troubling handshake failures.
Common Signs of an SSL Handshake Error
You might notice various symptoms including:
- Your WordPress site shows a “Your connection is not private” warning
- cURL errors in WordPress admin (like cURL error 60)
- Plugins that use external APIs failing to load
- Unsuccessful critical auto-updates due to failed HTTPS connections
What Causes SSL Handshake Errors Between IONOS and WordPress?
There can be multiple reasons for the SSL handshake to fail, including:
- Expired or improperly installed SSL certificates
- Misconfigured HTTPS URLs in WordPress settings
- Outdated SSL libraries (e.g., cURL, OpenSSL) on your hosting server
- Plugin conflicts, especially with security/firewall or caching plugins
- Incorrect time settings on your server or local machine
- Cloudflare or third-party DNS settings affecting SSL behavior
Step-by-Step Fixes for SSL Handshake Errors
Let’s break down a set of reliable troubleshooting approaches specifically adapted for WordPress sites hosted on IONOS.
1. Check and Reinstall Your SSL Certificate
IONOS provides free SSL certificates with most hosting plans. A corrupted or expired certificate is usually the primary reason behind HTTPS errors.
- Log into your IONOS Control Panel
- Navigate to SSL Certificates section
- Select your domain and click “Reinstall” or “Manage”
- Make sure your certificate is both active and properly assigned
Once done, clear browser caches and restart your local network connection to test the changes.
2. Verify WordPress Address and Site Address Settings
On WordPress, go to:
Settings → General
Make sure both the WordPress Address (URL) and Site Address (URL) are set to use https:// rather than http://.
Also, verify that your .htaccess file includes a redirect rule forcing HTTPS:
RewriteEngine On
RewriteCond %{HTTPS} off
RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]
3. Update PHP and cURL Libraries
IONOS may not use the absolute latest PHP or cURL versions by default. These libraries handle secure communication between your WordPress site and external servers.
- Log into IONOS and access your server via SSH or FTP
- Check PHP version using:
php -v
- To check the cURL version:
curl -V
If either of them is outdated, you can update these via your hosting management settings or contact IONOS technical support for an upgrade recommendation.
4. Temporarily Disable Plugins
Sometimes, security plugins like Wordfence, iThemes Security, or caching systems can interfere with SSL communications.
Steps to test this:
- Log into your WordPress dashboard
- Go to Plugins → Installed Plugins
- Temporarily deactivate all plugins
Try accessing your site after each plugin has been re-enabled to pinpoint the culprit.
5. Configure Cloudflare or External DNS Tools (If Used)
If you use Cloudflare for performance or firewall services, its SSL mode might be misaligned with IONOS settings. Log into your Cloudflare dashboard and check the SSL/TLS tab:
- Set the SSL mode to “Full” or “Full (Strict)”, not just “Flexible”
- Purge cache and DNS
- Allow some time for the DNS propagation to complete
6. Correct Date and Time Settings
SSL certificates are time-sensitive. An inaccurate system date on your local machine or web server can lead to failed handshakes.
Ensure your local computer and server have correct timezone configurations. On Linux servers, use:
timedatectl
Misconfigured system clocks are rare but notoriously deceptive when troubleshooting SSL issues.
Advanced Debugging Tips
Enable WordPress Debug Logging
To collect more insights, add the following to your wp-config.php file:
define('WP_DEBUG', true);
define('WP_DEBUG_LOG', true);
define('WP_DEBUG_DISPLAY', false);
After saving the changes, reproduce the SSL handshake error and inspect the log file at /wp-content/debug.log.
Conduct an SSL Test
Use free tools like SSL Labs’ Server Test to inspect your domain’s SSL setup. The results will indicate misconfigurations, outdated ciphers, or certificate chain issues.
When to Contact IONOS Support
If all else fails, you may be dealing with a server-level inconsistency. IONOS offers expert support, and you should reach out if:
- Your SSL reinstall attempts fail to resolve the issue
- Your WordPress version or server stack is deeply misaligned
- You suspect deeper SSL-related errors such as issues in
openssl.cnf
Provide them with detailed logs, screenshots, plugin history, and timestamps of the failures.
Preventing Future SSL Handshake Errors
To avoid reoccurring issues, follow these best practices:
- Use a plugin like Really Simple SSL to manage HTTPS settings safely
- Keep all plugins, WordPress core, and themes up to date
- Regularly renew and verify your SSL certificate on IONOS
- Schedule semi-annual SSL tests using third-party tools
- Create server snapshots before making major changes
Conclusion
Fixing SSL handshake errors between IONOS and WordPress may seem intimidating at first, but they’re usually preventable and reversible with the right steps. Whether caused by certificate misalignment, outdated libraries, or external service conflicts, following the above approaches should guide you toward resolution.
SSL is no longer a ‘nice to have’ — it’s a requirement. Protect your site, preserve your SEO rankings, and ensure smooth user experiences by proactively managing SSL configurations.
