ERR_SSL_PROTOCOL_ERROR: what it is and 3 effective ways to repair it

Whenever you access a website, your browser will request the site’s SSL certificate to establish a secure connection. SSL is a credential that proves a website’s legitimacy and is an essential element of the HTTPS protocol.

When initiating an SSL connection, web browsers also provide the website server with a client authentication certificate. This process is known as the TLS handshake.

After the authentication process completes, data transmission will occur, and the browser can display the web page. Otherwise, it will show different error messages depending on the issue, including ERR_SSL_PROTOCOL_ERROR.

The cause of this error is difficult to discern. It may be caused by an error on the website or the visitor’s end.

For visitors, old browser extensions, outdated SSL caches, or the QUIC protocol may be the culprit. It is also possible that the Windows Defender Firewall or an antivirus program is blocking the secure connection.

When encountering ERR_SSL_PROTOCOL_ERROR as a visitor, try:

• Disabling an outdated or problematic browser extension.
• Temporarily turning off firewall or antivirus.
• Clearing browser cache.
• Disabling QUIC protocol.
• Fixing the system date and time.

If none of the solutions above work, the problem should be with the website. Use website checker tools to verify whether the website is down for everyone else or just you.

On the website’s end, a misconfigured SSL is a common reason. For instance, this error may appear when forcing HTTPS without a valid SSL certificate installed. Similarly, not forcing HTTPS on an SSL-certified website may cause the same issue.

Error code	Connection refused
Error type	Network communication protocol error
Error causes	Network problem Incorrect SSH installation Wrong credentials Security system configuration

How to fix ERR_SSL_PROTOCOL_ERROR – video tutorial

If you prefer a visual guide to fixing this error, the video tutorial below is an ideal option. If you prefer a written guide, skip to the next section.

3 efficient steps to fix ERR_SSL_PROTOCOL_ERROR

Even though it is difficult to pinpoint what causes this error, there are three typical steps to fixing it for both site owners and visitors.

These methods include making sure SSL is installed, forcing HTTPS, and clearing the browser’s cache and SSL state.

1. Make sure SSL is installed on your website

Forcing HTTPS without having SSL installed will make your website inaccessible, showing the ERR_SSL_PROTOCOL_ERROR. This happens when websites don’t have the certificate required to enable HTTPS connections.

If you host your website at Hostinger, use the hPanel control panel to check whether SSL is installed:

1. Open hPanel and click the Websites section.

2. Select the website in question and click Dashboard.

3. Go to Security on the left side menu and click SSL.

A green check mark indicates the website’s SSL is installed and active. Otherwise, you need to get an SSL first before enabling HTTPS.

Since many companies offer different types of SSLs, choosing one may be challenging. Follow these tips to help you purchase the right certificate:

• Choose a legitimate company. Make sure to buy a valid certificate from a reliable SSL provider to ensure its safety and legitimacy. Read user reviews and testimonies before finalizing your purchase.
• Know your use case. Depending on the type, SSL can support a different number of domains. For example, a multi-domain SSL protects multiple domains, while a wildcard SSL protects the main domain and its subdomains.
• Look for warranty and support. Pick a company that offers a warranty and 24/7 customer support. These features let you quickly fix or refund your SSL with the provider’s help.
• Consider your budget. SSLs vary in price, but you can get a free certificate from a nonprofit like Let’s Encrypt. Obtaining and installing Let’s Encrypt SSL has its benefits and is free, but you must renew it every 90 days.

The buying process of an SSL certificate differs depending on the provider. But generally, the steps are as follows:

1. Generate Certificate Signing Request (CSR). It is the encoded information about your website’s domain name, contact details, company, and public key.
2. Purchase the SSL you want.
3. Submit your CSR to the Certification Authority (CA) or the certificate issuer.
4. Wait until the domain validation process completes.
5. Install the SSL certificate on your website.

Alternatively, purchase any Hostinger web hosting plan, and get a free lifetime SSL service. For enabling a secure connection, these free SSLs are enough. They offer the same level of protection as the paid ones.

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2. Force HTTPS connection on your website

After installing SSL, your website will be available in HTTP and HTTPS protocols. Unless forced to run on HTTPS, your website will run on HTTP by default.

If the previous step does not solve the issue, check whether your website has HTTPS forced. Not forcing HTTPS is also a possible cause for ERR_SSL_PROTOCOL_ERROR.

Remember, switching from HTTP to HTTPS can cause issues for your website, including inaccessibility. For this reason, create a backup of your website before making further changes in case it goes wrong.

With Hostinger, all SSL certificates force HTTPS by default. To enable HTTPS manually using hPanel, follow these steps:

1. Open hPanel and click the Websites section.

2. Select the website in question and click Dashboard.

3. Go to Security on the left side menu and click SSL.

4. Click on the three dots and select force/unforce SSL.

These steps may differ for different hosting providers and control panels. Consider using other methods to force HTTPS:

• Edit the code on your .htaccess file to force HTTPS. This file is found on your WordPress site root directory.
• Install and force SSL certificate using WordPress for websites made using WP.

Before generating the SSL credentials, you must confirm that your website’s DNS settings have been fully propagated. Use online DNS checker tools such as WhatsMyDNS to track the propagation. Usually, the process can take up to 24 hours.

Installing an SSL certificate before the DNS fully propagates may cause the ERR_SSL_PROTOCOL_ERROR issue. The reason is that the certificate will have an incorrect associated domain name. In this case, try uninstalling the SSL and redo the troubleshooting steps.

3. Clear your browser’s cache

After following the previous two steps, you should have resolved the issues on your website’s end. If the error persists, the problem is likely with your browser.

Browsers store information about the visited websites, including images, texts, files, and SSL, as a cache. When you revisit the website, your browser will retrieve the required resources from the cache instead of the site’s web server. This allows the web page to load more quickly.

Benefits aside, keeping an old cache may cause problems. If any important changes are made to the site, your browser may not be able to display it until it retrieves the new information.

Clearing your browser cache will force it to renew the cache with updated information. Therefore, doing so may help resolve various issues on your browser, including SSL errors.

Depending on the browser, the steps of clearing the cache may slightly differ. However, the overall process is similar. To clear the cache on Google Chrome, do the following:

1. On your Google Chrome browser window, click the three little dots icon next to the address bar.

2. From the drop-down menu, click More tools -> Clear browsing data.

3. Select your preferred Time range – the option ranges from Last hour to All time. We recommend choosing All time to ensure all caches are deleted.

4. Choose which type of website data you want to delete. To clear caches, check Cached images and files only. You may also delete Browsing history and Cookies and other site data.
5. Click the Clear data button to proceed.
6. Restart your browser.

Keep in mind that you may experience a slower site loading speed after clearing your cache. Moreover, wiping all browsing data will sign you out of most websites.

Similar to Google Chrome, other browsers’ clear cache functionality is accessible through the settings menu. Excluding Safari, most browsers also allow you to select the type of browsing data and the time frame of deletion.

In addition to caches, clearing the browser’s SSL state is another method to resolve the error.

Your browser stores an SSL cache for a similar purpose. If the website updates its certificate, this cache may cause an SSL connection failure because the cached certificate does not match the new one.

The steps of clearing the SSL state vary depending on the operating system and browser. For Google Chrome users running Windows, do the following:

1. Open your browser window, click the three little dots icon, and select Settings.

2. On the left sidebar, go to System -> Open proxy settings.

3. The Internet Properties pop-up window will appear. Go to the Content tab and click Clear SSL state.

4. Press OK to confirm.

For older versions of Google Chrome, open the Settings menu -> Advanced settings. The Open proxy settings button is under the Network tab. Alternatively, open the same window by typing Internet properties and hitting Enter. However, this method only works on newer Windows operating systems.

You may also clear the SSL state with Manage certificates on Google Chrome:

1. Navigate to the three dots menu on the browser window and click Settings.
2. On the left sidebar, select Privacy and security -> Security.

3. Scroll down and click Manage certificates. It shows a list of the SSLs cached by Google Chrome.

4. Navigate through the different tabs. After selecting an SSL, click Remove to clear the SSL state.

5. Click the Close or X button.
6. Restart Google Chrome to finish the process.

How different browsers display ERR_SSL_PROTOCOL_ERROR

Although all browsers can face this problem, they may show different error messages. Let’s take a look at how several popular browsers display ERR_SSL_PROTOCOL_ERROR.

Google Chrome

When you encounter ERR_SSL_PROTOCOL_ERROR on Google Chrome, you will get the “This site can’t provide a secure connection” message. The exact error code is shown at the bottom.

Google Chrome explains that the website sent an invalid response. You may choose to Reload or Try running Windows Network Diagnostics.

Opera

Similar to Chrome, Opera users will also get the ERR_SSL_PROTOCOL_ERROR code. Opera will show “This site can’t provide a secure connection” with a description saying that the website sent an invalid response.

Clicking the Try running Windows Network Diagnostic will bring up the troubleshooting tool.

Microsoft Edge

Microsoft Edge will display the “The connection for this site is not secure” message when encountering the ERR_SSL_PROTOCOL_ERROR issue. The exact code will appear at the bottom of the error message.

Similar to the previous browsers, it also provides the Try running Windows Network Diagnostics clickable text.

Mozilla Firefox

Mozilla Firefox gives visitors a detailed description of the error message. When encountering a similar issue, the browser will warn you about a failed secure connection and show the SSL_ERROR_RX_MALFORMED_HANDSHAKE code.

You will get an explanation of what causes the error and what to do about it. Firefox users may retry by clicking the Try Again button or Learn more… to get further information about the error.

Conclusion

The ERR_SSL_PROTOCOL_ERROR occurs when a website cannot provide a secure connection. This may be due to issues on the website, such as not forcing HTTPS or not having an SSL certificate.

A problem with your browser may also cause the ERR_SSL_PROTOCOL_ERROR. Moreover, depending on the browser, the error message may appear differently.

While the error may seem tricky to resolve, we have provided three steps to help you fix this error as a website owner or visitor:

1. Ensure your website has SSL installed. To do this, check your hosting control panel. Having HTTPS enabled without the certificate can lead to an SSL connection error.
2. Force HTTPS on your site. After your website has an SSL installed, force HTTPS by configuring it through your hosting control panel, .htaccess file, or the WordPress dashboard.
3. Delete your browser cache. The browser may store an old SSL cache which can cause the connection issue. Clearing the cache and SSL state allows the browser to renew the existing information.

We hope this article helps you troubleshoot the error. If you have any questions or alternative solutions, leave a comment below.