14 Fixes For “SSL_error_rx_record_too_long” Mozilla Firefox Error

What Does SSL_error_rx_record_too_long Error Mean?

A server-side misconfiguration usually causes the SSL_error_rx_record_too_long error message from Mozilla Firefox. Despite many of these instructions claim, there isn’t usually anything a user can do to fix the SSL_error_rx_record_too_long message.

The majority of the advice is hazardous. It requests that the user make a change to accommodate poor security on the side of the website you are attempting to visit.

Let’s begin by looking at the two most common server-side sources of the message SSL_error_rx_record_too_long error:

  • You’ve misconfigured the listening port: If you want your website to establish secure connections, you’ll need to change it to Port 443.
  • You don’t have an up-to-date TLS version:  This issue first appeared ten years ago with the introduction of TLS 1.2, and it has resurfaced with TLS 1.3.

The error code SSL_error_rx_record_too_long message is caused by one of these two server-side errors the great majority of the time.

Fix the SSL_error_rx_record_too_long Error Message in Mozilla Firefox (visitor)? 

You can use the following given methods to fix the SSL_error_rx_record_too_long error message.

  1. Configure the TLS Version Acceptance Level 
  2. Clear Browsing Cache Memory
  3. Substitute the HTTPS Protocol
  4. Change Proxy Settings
  5. Disable Your Antivirus and Firewall  
  6. Configure Trusted Sites 
  7. Update Firefox Browser
  8. Use a Reliable SSL Certificate
  9. Verify Port 443 Status
  10. Uninstall Mozilla Firefox Extensions
  11. Make use of a VPN.
  12. Open Mozilla Firefox in Safe Mode 
  13. Update SSL/TLS Library
  14. Configure the Listening Port 80

1. Configure the TLS Version Acceptance Level 

Some certificates are compatible with previous TLS versions like TLS 1.1 and TLS 1.2. At the same time, Mozilla Firefox security settings are set to accept just the most recent TLS version, TLS 1.3. Mozilla Firefox displays the SSL_error_rx_record_too_long  issue when it meets a certificate that supports an older TLS 1.2.

You may make Mozilla Firefox allow websites that use SSL certificates that support older TLS 1.2 by setting the TLS acceptance level. You’ll still be viewing a website that uses the HTTPS protocol to encrypt data. It is the safest way to fix the SSL_error_rx_record_too_long  problem.

  • In the Mozilla Firefox address box, type “about:config.”
  • To accept the risk, click the I accept the risk button.
accept the risk button
  • Now, double-click on “security.tls.version.max” in the search results.
  • Set the value of security.tls.version.max to “3.”
  • In the search box, write “security.tls.version.min” and double-click it.
  • Set the value of security.tls.version.min to “0.”

2. Clear Browsing Cache Memory

Sometimes the SSL_error_rx_record_too_long  problem has been resolved on the server-side. Mozilla Firefox cache memory is still displaying old information. This problem may be determined by clearing your browsing history, cookies, and cache memory:

  • Open Mozilla Firefox and select Options from the drop-down menu in the top-right corner.
  • From the left menu bar, select history.
select history
  • In the history data tab, choose Clear Data.
  • The Cookies and Site Data window, as seen on a computer screen.
Clear Data
  • Select all of the options and then press the Clear Now button.

3. Substitute the HTTPS Protocol

Moving from HTTPS to HTTP is one of the most straightforward fixes for the SSL_error_rx_record_too_long  problem. Note: We’re notifying you that this is a possible solution to the problem. However, connecting to a website using the unsecured HTTP protocol is not a good idea since it puts you at risk.

Only this solution will work if the site doesn’t have a 301 redirect.

  • The website you’re trying to access will begin with HTTPS:// in the address bar. 
remove the letter "s"
  • Simply remove the letter “s” from HTTPS:// and use HTTP:// to access the website.
remove the letter "s"

However, if the website has already been switched to HTTPS, this approach may not work.

4. Change Proxy Settings

Incorrect proxy connections can also cause the SSL_error_rx_record_too_long  message. You can disable proxy settings to check if this is the cause of the error by doing the following:

  • Open Mozilla Firefox.
  • Look for “settings” in the menu.
  • Firstly, go to the Network Settings at the bottom of the General Tab.
Network settings
  • You’ll find a box labeled Configure Proxy Access to the Internet, where you must select the “No Proxy” option.
 No Proxy
  • Restart the browser by clicking the OK button.

To reload a web page, Ctrl+Shift+R or Shift+click Reload work as a better shortcut.

5. Disable Your Antivirus and Firewall  

Switching off your firewall and antivirus is a hazardous move that we never advise. If you use this process, make sure to reactivate the solution. Enable antivirus once you’ve gained access to the desired website.

windows security

SSL scanning is available in most antivirus and firewall software. Suppose you’ve told browsers to ignore SSL-related errors. The antivirus program would still block websites with faulty SSL certificates.

Simply look for SSL-related options in your antivirus software or firewall. It might be called things like “HTTPS Scanning,” “Scan SSL,” “display the safe result,” “don’t scan encrypted connections,” and so on. Disable these options. If you can’t find a setting area, you can temporarily disable the antivirus/firewall.

6. Configure Trusted Sites 

When you add a webpage to your “trusted sites” list, all browsers will trust it regardless of its SSL/TLS setup. To add a webpage to your trusted sites list, follow these steps:

  • In the Windows search box, type Internet Options.
Internet Options
  • Select the Security tab in the Internet Properties box.
trusted websites
  • Choose from a list of trusted websites.
  • A private window will pop up when you click the Sites button.
  • Add the website’s URL that is displaying the error notice manually. After that, select Add and then Close.
Add the website's URL
  • Press on Apply and then OK to return to the Internet Properties window. That concludes our discussion.

7. Update Firefox Browser

It is critical to update your browser frequently because the developers may have fixed the problem for you. Check to see if your Mozilla Firefox is up to date. You can quickly update it by following the steps below.

  • To access the menu, click the three horizontal lines in the top right-hand corner of your browser.
  • Select the ‘Help’ option from the drop-down menu.
About Firefox
  • Go to ‘About Firefox,’ and you should see the graphic below if it has already been updated.
  • Mozilla will start scanning for updates automatically.
scanning for updates

8. Use a Reliable SSL Certificate

It’s also possible that the SSL certificate is malfunctioning. It resulted in the SSL_error_rx_record_too_long issue. 

In that scenario, choose an SSL certificate that matches the bill. It should be based on the type of website you run. Although free SSL certificates are available, they may not always be sufficient. 

As a result, purchase an SSL certificate from a reputable certificate authority. Consider this an investment because SSL certificates improve your website’s overall rating in search results.

9. Verify Port 443 Status

If Port 443 on your website isn’t open, that could be the problem. You can check this by following the method listed below.

  • Before the IP address, type ‘HTTPS’ in the address bar.
  • To verify if Port 443 is open, you can use tools like Netcat and Ncat.
  • Windows users can open the Command Prompt and run ‘tracert xyz.com.‘ to obtain your website’s IP address.
  • Alternatively, you may check a website’s IP address by typing the domain name and following the instructions above.

10. Uninstall Mozilla Firefox Extensions

Extensions are software modules that allow the browser to perform one or more functions. If you downloaded one that is incompatible, it might affect the browser. As a result, the SSL_error_rx_record_too_long error may occur. So, uninstall Mozilla Firefox Extensions from your website and see if that fixes the issue. To uninstall Extensions, follow the instructions outlined below.

  • To enter the main menu, click the three horizontal lines in the top right-hand corner.
  • From the dropdown menu, select the ‘add-ons’ option.
  • You may also visit the add-ons page by pressing Ctrl+Shift+A while the Mozilla Firefox window is active.
  • To uninstall an extension, click the three dots next to its name, as seen in the image, and then select ‘Disable.’
uninstall an extension
  • Finally, go to the main menu and select ‘Help’ from the drop-down menu.
  • Locate and select the ‘Restart with add-ons deactivated’ option from the available options.

11. Make use of a VPN

Many people have claimed that utilizing a VPN helped them overcome the ‘SSL_error_rx_record_too_long’ issue. It’s worth a shot, even if there’s no assurance it will always work. To test it out, you can use any VPN.

12. Open Mozilla Firefox in Safe Mode 

Security add-ons don’t always open websites with incorrect SSL certificates. All add-ons will be deactivated when you restart Firefox in safe mode, and you will be able to visit the site.

  • To launch Firefox in safe mode. Go to the Firefox menu and select “Safe Mode” (three lines on the right side of the window).
  • Go to the Help section.
  • Select Restart with Add-ons Disabled from the menu.
  • Choose the Restart Tab.
  • Start in Safe Mode by clicking the button.

Resolve SSL_error_rx_record_too_long (Website Owner)

13. Update SSL/TLS Library

When your server or system does not support your TLS 1.3 version, SSL_error_rx_record_too_long error may show. This problem can be solved by updating OpenSSL’s SSL library. TLS 1.3 is already supported by most browsers, and many servers are striving to upgrade to support it. As a result, ensure the TLS 1.3 is turned on.

At the very least:

  • Ensure you’re using TLS 1.2.
  • Deprecated versions (such as SSL 3.0 and TLS 1.0, and TLS 1.1 beyond March 2020) should be disabled immediately.

14. Configure the Listening Port 80

All traffic between a web browser and your server is routed over port 80 (commonly known as the “listening port”) if you lack an SSL/TLS certificate. While installing an SSL certificate on your server, you can use the secure HTTPS protocol by enabling port 443 for data transmission.

If your SSL certificate isn’t configured to allow the use of port 443, any online traffic for the site will encounter difficulties.

The TLS/SSL certificate can be configured in a variety of ways on each server.

If you’re using any server, try searching for “Port 443 + HTTPS + Your server name” to obtain more information.


We’ve included a few simple workarounds that should solve the SSL_error_rx_record_too_long error message. If they don’t, contact the Server Administrator to avoid losing out on prospective Mozilla Firefox visitors to your website. 

Forcing your web browser to ignore SSL_error_rx_record_too_long. You’ll be visiting a website that isn’t encrypting your data, exposed to data theft and man-in-the-middle attacks.

Frequently Asked Questions

What is SSL_error_rx_record_too_long error?

SSL_error_rx_record_too_long is a bug that only affects Mozilla Firefox users. It’s a rather typical error and problems with the SSL certificate cause it. When a server opens a port for a client to connect to, but the SSL certificate is not configured correctly, this error message occurs.

How do I fix Secure Connection Failed in Firefox?

To remedy this, go to the settings section of whatever security software you’re using and look for the SSL scanning feature. Once you’ve found it, uncheck the box that says it’s turned on. You should try re-accessing the page after disabling this function in your security program.

Why does Firefox say my connection is not secure?

Firefox When the website’s validation certificate is not completed or valid. The Mozilla  Firefox error “your connection is not secure” appears. Firefox closes the connection to the website and displays the notice if the certificate cannot be validated. The error line “Your connection is not secure” is sometimes known as an SSL error.

Why am I getting “secure connection failed” in Firefox?

Firefox may detect that the website’s security certificate is expired or invalid due to an inaccurate system date. Make sure your computer’s date, time, and time zone are correct. See How to troubleshoot time-related problems on secure websites for additional details.

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Abdul Rahim has been working in Information Technology for over two decades. Learn how Abdul got his start as a Tech Blogger , and why he decided to start this Software blog. If you want to send Abdul a quick message, then visit his contact page here.