How to Resolve Error Code: ssl_error_rx_record_too_long?

Jackson Gordon

Last update on: June 18, 2025

Home > How To > How to Resolve Error Code: ssl_error_rx_record_too_long?

Contents

If you’re browsing a website and encounter the error message “ssl_error_rx_record_too_long”, it can be both confusing and frustrating. The error usually shows up in Firefox and points to a failure during the SSL/TLS handshake between your browser and the server. In simple terms, the browser was expecting a secure response (encrypted), but received something else—usually due to server misconfiguration or network interference.

This article will explain what the error means, why it happens, and most importantly, how to fix it.

1. What Is ssl_error_rx_record_too_long?

The error ssl_error_rx_record_too_long is tied to Secure Socket Layer (SSL) encryption, which is the technology used to establish a secure connection between a web browser and a server.

When you see the ssl_error_rx_record_too_long code in Firefox, it typically means:

The browser tried to establish a secure HTTPS connection.
It received an unexpected or malformed response during the SSL/TLS handshake.
In response, the browser stopped the connection to safeguard your data.

Common Error Message Displayed in Firefox:

2. Common Causes of ssl_error_rx_record_too_long

Server Misconfiguration
The most common cause is a misconfigured web server. The server might be using HTTP instead of HTTPS on port 443, or SSL/TLS might not be set up correctly.
Wrong Port Configuration
HTTPS should run on port 443. If the server is configured to serve HTTP content on port 443, the browser will be confused during the handshake.
Untrusted or Self-signed SSL Certificates
If the website is using an improperly signed certificate or none at all, this error can occur.
Outdated Browser
Sometimes, an outdated browser version may not support modern TLS protocols properly.
Firewall or Proxy Interference
Some firewalls or proxies might tamper with SSL traffic, resulting in incomplete or malformed records.

3. How to Fix the Error Code: ssl_error_rx_record_too_long?

3.1 Check the Website (Client-Side Check)

If you’re a visitor encountering this error:

Try Another Browser: Open the same site in Chrome or Edge. If it works there, it’s a Firefox-specific issue.
Clear Cache and Cookies: Access Firefox Settings, head to Privacy & Security, then clear all data under the Cookies and Site Data section.
Disable Proxy Settings (If Any):From Firefox’s Settings menu, go to General > Network Settings > Settings > Pick “No proxy” or “Use system proxy settings” > Click OK to save.
Turn Off Third-Party Extensions: Especially ones related to VPNs, proxies, or HTTPS filtering.
Temporarily Disable Antivirus SSL Scanning:Navigate to your antivirus software’s settings and disable the HTTPS scanning feature to test for a resolution.

3.2 For Website Owner or Admin

If this error is happening on your own server, the problem is likely due to misconfiguration. Follow these steps:

A. Ensure HTTPS is Configured on Port 443

Verify that your server accepts HTTPS connections on port 443 and is correctly set up with SSL.

For example, on Apache:
ensure https is configured on port 443 apache

Check that:

The correct port (443) is used.
SSL is enabled (SSLEngine on).
Paths to certificate and key files are valid.

For Nginx, a correct server block looks like:
ensure https is configured on port 443 nginx

B. Install a Valid SSL Certificate

Use an SSL certificate that’s properly signed by a recognized CA, for example, Let’s Encrypt, Sectigo, or DigiCert.

Follow these steps to install a no-cost HTTPS certificate via Let’s Encrypt:
sudo apt install certbot python3-certbot-nginx
sudo certbot –nginx

Certbot will automatically configure your Nginx/Apache server with a valid certificate.

C. Restart Your Web Server

After making changes to your configuration or installing a new certificate, restart the server:

For Apache: sudo systemctl restart apache2
For Nginx: sudo systemctl restart nginx

3.3 Advanced Fixes and Tips

A. Use Online SSL Checkers

Use tools like:

SSL Labs SSL Test
Why No Padlock

These can help diagnose if your certificate is trusted, expired, or misconfigured.

B. Ensure No HTTP on Port 443

If your server responds with plaintext HTTP on port 443, the browser will see this as a malformed SSL record.

Use curl to test: curl -v https://yourdomain.com

C. Check Firewall or Load Balancer Configuration

If you’re behind a load balancer or proxy (like HAProxy or Cloudflare), make sure it is configured to handle HTTPS properly or pass SSL traffic to your origin server.

Verify that HAProxy’s configuration includes bind *:443 ssl crt /etc/ssl/private/mycert.pem for correct SSL binding on port 443.

4. Conclusion

The ssl_error_rx_record_too_long error is a signal that something is wrong with the SSL/TLS connection—usually a server-side configuration problem. Whether you’re a casual user or a website administrator, the steps outlined in this article can help you identify and resolve the issue.

If you’re just visiting the site, try a different browser, disable extensions, or check your network. If you’re managing the site, double-check your SSL certificates, web server settings, and ensure port 443 is configured correctly for HTTPS.

Understanding how SSL/TLS works and ensuring it’s properly implemented will prevent this error and provide users with a safe and secure browsing experience.