What is ERR_SSL_PROTOCOL_ERROR, and how do I fix it?

With ever-rising internet usage, users are sharing more sensitive information online than ever before. With the number of growing online transactions, TLS and SSL have become vital to include in a server over a computer network.

TLS and SSL usage ensures that a user’s data is transmitted and authenticated securely between servers over a computer network. However, this secure transmission sometimes fails to execute, and a user faces an ERR_SSL_PROTOCOL_ERROR.

Common causes of this error may include an outdated or misconfigured browser, incorrect date and time settings, issues with SSL certificates, firewall or antivirus interference, and problems from the server’s side. The error is highly noticeable, as it hampers a website’s accessibility and affects its user experience. This makes the website vulnerable to security breaches and hacking related to the user’s personal and sensitive information. However, you need not worry since the error is usually fixable if you follow simple steps. This guide will show you the exact steps.

Note: If your website is hosted with Vodien, you are welcome to contact our support team to help you fix the ERR_SSL_PROTOCOL_ERROR message. Explore our web hosting and dedicated server hosting plans to learn more about the solutions we offer.

Common Causes of ERR_SSL_PROTOCOL_ERROR

1. Outdated or Misconfigured Browser

An outdated or misconfigured browser may not establish a secure connection over HTTPS (HyperText Transfer Protocol Secure) with the web server. Updated SSL/TLS protocols may not be supported, the browser might be unable to validate the SSL/TLS certificate, or it may lack the ability to support the latest algorithm the server uses. Additionally, browser settings or extensions might interfere with the SSL handshake, causing the error. Regularly updating your browser and reviewing its settings can help prevent these issues.

2. Incorrect Date and Time Settings

SSL/TLS certificates rely on an accurate time and date to validate the server they connect with. Incorrect date and time settings on a user’s computer can lead to the ERR_SSL_PROTOCOL_ERROR, as the certificates may appear expired or not yet valid. Keeping your system clock synchronized with an accurate time source helps prevent this error.

3. Issues with SSL Certificates

Common SSL certificate errors, such as expired certificates, incorrect or unregistered domain names, and invalid users due to compromised or revoked user certificates, may also cause this problem. Incomplete certificate chains or mismatched domains also contribute to this error. Ensuring your SSL certificate is properly installed, up-to-date, and configured for your domain is essential to prevent the issue.

Pro Tip: If your SSL certificate has expired, you need to get a new one immediately. Staying on HTTP will hamper your SEO performance, and also greatly disrupt the experience of your website users. Get an SSL certificate from Vodien today and get a secure connection with the highest level of firewall and malware protection.

4. Firewall or Antivirus Interference

Firewall and antivirus software can sometimes interfere with secure connections, mistaking them for security threats. This can lead to the ERR_SSL_PROTOCOL_ERROR. Overly aggressive security software may flag legitimate SSL/TLS traffic as a mistaken threat, disrupting the connection. 

Users may need to adjust their firewall or antivirus settings, temporarily disable these protections, or create exceptions for trusted websites to resolve the issue. You may have to change the settings manually to eliminate the error. You can do this in Windows Firewall Settings, as shown below:

5. Server-Side Problems

Changing your web hosting servers or installing a new SSL/TLS certificate can lead to misconfigured SSL/TLS settings. The protocol version must also be up-to-date because outdated SSL/TLS protocols can cause this problem, too. Server misconfigurations, such as incorrect key files or improper virtual host setups, can trigger the ERR_SSL_PROTOCOL_ERROR message. Regularly reviewing and testing server configurations can help identify and correct these issues.

Note: Server-side issues are among the most common reasons this error occurs. Especially if you have recently changed or updated some settings on your server, or if you have just set up a new website on the server. In cases where the website is not yet live, you might also encounter a DNS_PROBE_FINISHED_NXDOMAIN error.

How do I fix the ERR_SSL_PROTOCOL_ERROR?

Try the steps shown below to fix this error message:

1. Clear Browser Cache and Cookies

A simple caching issue can cause an ERR_SSL_PROTOCOL_ERROR on localhost. Most browsers store cache, like images, files, etc., when you browse the internet. The reason for this is to load the content again quickly if you visit the site again. Therefore, clearing the browser cache and cookies can help a user get rid of such errors. One can follow these steps:

For Chrome:

1. Open three vertical dots on the upper right side.

1. Click on the option to clear browsing data. 
2. By default, a banner will open. Select options for website cookies, cache, and images. You can also select the time period from the drop-down menu.

The steps are more or less similar for other popular browsers as well.

Firefox: 

1. Open three horizontal dots on the upper right side.
2. Go to Settings. 
3. Click on privacy and security.
4. Select the option clearing cache and data. 

Safari:

1. Find preferences and settings in the Safari browser. 
2. Go to the privacy tab. 
3. Click on the Manage Privacy and Data option. 
4. Click on Manage website data, and then select all or clear sites individually. 

Edge:

1. Go to Settings. 
2. Look for privacy, search, and services. 
3. Scroll down to clear browsing data and select them accordingly. 
4. Under the time range.
5. Select a time range and click on cookies and browsing data.
6. Proceed with clearing the cache.

2. Check for Issues With Your SSL Certificate

An ERR_SSL_PROTOCOL_ERROR on localhost WordPress can occur if your SSL certificate is incorrectly installed, expired, mismatched with the domain name, missing intermediate certificates, or if there are configuration issues on the server. Additionally, outdated protocols, blacklisted certificates, mixed content, or DNS misconfigurations can also cause this error. Here are some ways to check for issues with your SSL certificate: 

1. Installation:

Sometimes, users try to force HTTPS on their website servers when a certificate is either not installed or installed improperly. To verify, follow these steps:

For Chrome, Firefox, and Edge: 

1. Open a website’s server. 
2. Click the padlock on the panel’s left side of the displayed link address. 
3. A banner for information will open, showing a lock icon that says this website’s connection is secure. 

For Safari:

1. Go to the website’s server. 
2. Double-click on the padlock in the website’s banner.
3. Click on the details that appear in the window. 
4. If the padlock is there, your SSL certificate is installed and secure. 

For a more advanced view, a user can use tools that tell if an SSL certificate is properly installed or not. If the certificate is missing, then get it installed.

2. SSL configuration:

To fix ERR_SSL_PROTOCOL_ERROR as a user, you must use the correct SSL certificate configuration. Fixing your SSL configuration requires two things to be kept in check: strong encryptions like TLS 1.2 or 1.3 and discarding outdated protocols like SSL 2.0, 3.0, or TLS 1.0.

In order to fix the SSL configuration, one can refer to these steps: 

 For all browsers: 

1. By following the steps given above, view the SSL certificate. 
2. Open its details and look for the expiration date, the certificate version, and whether the cipher suite is up-to-date and secure. 
3. Ensure that your website uses an up-to-date SSL certificate to ensure proper configuration of the SSL certificate.
4. Lastly, if your SSL certificate has expired, it will show up when you look for SSL configuration in your browser. Ensure you install a new SSL certificate from a proper certificate authority and eliminate the error.

Pro Tip: Use Qualys SSL Checker to inspect your SSL certificate.

3. Check and Update Your Browser

The ERR_SSL_PROTOCOL_ERROR can occur when using an outdated browser to surf the Internet, which can cause secure connection issues. Therefore, updating your browser to the latest version is important, as it fixes bugs and adds new features in every aspect. One can update the browser after checking for updates on the Microsoft Store for Windows and the Apple Store for MacOS users. 

Here are the links to download the latest versions of:

• Chrome: https://chrome.en.softonic.com/download 
•  Firefox: https://www.mozilla.org/en-US/firefox/new/  
•  Edge: https://microsoft-edge.en.softonic.com/download 
•  Safari: https://support.apple.com/en_IN/downloads/safari 

4. Disable Browser Extensions

Using multiple extensions in your browser can affect its functionality, which may cause the ERR_SSL_PROTOCOL_ERROR localhost in this case. Disabling the browser extensions temporarily may help fix this error. 

Follow these steps to disable the extensions:

On Chrome: 

1. Click on the upper three dots on the right side of Chrome.
2. Go to Settings.
3. Click on extensions. Go to Manage Extensions.

1. Select all, and then disable them.

On Firefox: 

1. Click on the three horizontal tab icons in the upper right. 
2. Click on the add-ons option. 
3. Select the option for extensions, go to manage extensions, and disable them.

On Edge: 

1. Click on the three dots in the upper-right banner in Edge.
2. Click on the option for extensions. 
3. Go to Manage Extensions and disable them. 

On Safari: 

1. Go to Settings. 
2. Click on the extensions tab and toggle off the switch for extensions.

5. Check Date and Time Settings

For the SSL/TLS protocols to function without the ERR_SSL_PROTOCOL_ERROR on localhost WordPress error, the date and time of the system must be correct. Thus, to check the ‘date and time,’ refer to the following steps: 

For Windows:

1. Press the Windows key and type ‘date and time.’ 
2. Check whether the date and time are accurate in the date and time menu.
3. If not, select your time zone by clicking on the banner on the right side of the time zone panel.

For macOS: 

1. From the upper-left corner, click on the Apple icon. 
2. Select a date and time from the menu.
3. Click on the correct time zone that you are in if your date and time are wrong.

6. Check Your Antivirus and Firewall

A few algorithms and rules disable access to various website servers, regardless of whether they pose a security risk. Thus, temporarily disabling the firewall or the antivirus might help fix ERR_SSL_PROTOCOL_ERROR. 

You can refer to these steps: 

For Windows: 

1. Go to Settings.
2. Then go to privacy and security.
3. Go to Windows Security. 
4. Click on virus and threat protection, then click on manage antivirus, and turn off the toggle for real-time protection. 
5. To turn off the firewall, click on firewall and network protection, then turn off the firewall on the domain network.

For macOS: 

1. Click on the upper-left apple symbol. 
2. Go to Settings.
3. Click on the network option.
4. Turn off the firewall toggle. 

Troubleshooting Tips for ERR_SSL_PROTOCOL_ERROR

Test with a Different Browser or Device

The user can also try accessing the same website with a different browser. This will help determine if the problem with website access is related to a particular browser or not. Users can access the website using a different device if the issue persists. Isolating the browser and device can help you figure out if the problem is related to a particular browser or device. 

Try accessing the website through a VPN 

You can try to access the website by using a VPN. If the website is loading successfully while using the VPN, it indicates that ERR_SSL_PROTOCOL_ERROR may be related to your network or internet service provider. This completes the purview of basic troubleshooting, providing the user with an understanding of ‘why’ the error persists. 

Contact your hosting provider or website owner

Even after trying all of the troubleshooting, if the ERR_SSL_PROTOCOL_ERROR on localhost persists and you are unable to fix it, contact your internet service provider (ISP). The reason is that it might be the case that your ISP’s SSL/TLS configuration requires an update, or there might be some other issue on the server’s side. One can visit their ISP’s website and then contact customer service to proceed with fixing the error.

Conclusion 

The ERR_SSL_PROTOCOL_ERROR is a common but fixable issue that affects secure website connections. You can resolve the error by following key troubleshooting steps—clearing browser cache and cookies, checking SSL certificate installation and configuration, updating the browser, disabling extensions, verifying date and time settings, and adjusting antivirus and firewall settings—and ensuring secure data transmission. 

If these steps do not resolve the issue, trying different browsers or devices, using a VPN, and contacting your hosting provider or ISP can help further isolate and fix the ERR_SSL_PROTOCOL_ERROR on localhost. Our guide provides practical solutions to quickly identify and address the root causes of the error, ensuring that your online interactions remain secure and seamless.