How to Fix ERR_SSL_PROTOCOL_ERROR in Windows

Err Sll Protocol Error On Windows

ERR_SSL_PROTOCOL_ERROR primarily emerges on web browsers. Although this error aims to discourage users from accessing potentially destructive websites, it occasionally appears due to network difficulties, corrupted or outdated system cache, and other reasons. This tutorial walks you through the primary causes of the ERR_SSL_PROTOCOL_ERROR message in Windows computers and details several approaches to fixing it.

Good to know: are you dealing with the network cable unplugged error? We show you how to fix it.


Below is a list of the primary reasons the error may emerge:

  • Expired SSL certificate: an SSL certificate is a specific code that encrypts the information sent over the Internet. An expired certificate no longer works to keep your info safe and exposes your data to possible cyber attacks.
  • Network problems: network problems occur when data can’t get from one place to another. It may be because there is no connection between the two places or something along the way is blocking or corrupting the data.
  • Deteriorated system cache: a cache is a reserved storage location on your system where it collects information so that it doesn’t have to look for it again the next time you want it. But sometimes the data stored in the cache gets corrupted, and when the computer tries to use it, several kinds of errors surface.
  • Malware activity: malware is software designed to disrupt or damage computer systems without the owners’ consent. This includes viruses, worms, trojans, and similar programs.

1. Clear Your Browser Cache and SSL State

These steps to clear browser cache and SSL State vary from one web browser to another. For the purposes of this tutorial, we are using Chrome throughout.

  1. Navigate to the top-right corner of your browser and click on the three-dot menu.
  2. From the drop-down, hover over “More Tools,” then select “Clear browsing data.”
Err Sll Protocol Clear Chrome Cache
  1. Now select “All time” from the drop-down menu and select “Clear data” to clear the browsing history.
ERR SLL Protocol - Chrome History
  1. Press the Windows + R keys to open Run on your computer.
  1. Type inetcpl.cpl and click “OK.”
ERR SLL Protocol -  Windows Run
  1. On the following page, navigate to the “Content” tab and click on the “Clear SSL state” button, then select “OK.”
ERR SLL Protocol -  Clear Ssl State

Tip: tired of seeing annoying cookie consent pop-ups every time you visit a website? We show you how to disable them.

2. Check Your System Clock

When the date or timezone settings on your computer are incorrect, several errors surface that cause problems with how your computer behaves. To fix this:

  1. Press the Windows + I keys to open Settings on your computer.
  2. Navigate to “Time and Language” and select “Date and Time.”
ERR SLL Protocol -  Date And Language
  1. Verify the current timezone, time, and date. Modify them accordingly.
ERR SLL Protocol -  Verify Current Date And Time

3. Disable Third-Party Browser Extensions and Antivirus Software

Browser extensions can sometimes cause problems such as ERR_SSL_PROTOCOL_ERROR, which is why you should disable any third-party browser extensions, at least temporarily.

  1. Move to the top-right corner of your browser and select the three-dot menu icon.
  2. Select “Settings” from the list of options.
  3. Click on “Extensions” in the menu on the left.
ERR SLL Protocol -  Chrome Extensions
  1. Click on the toggle next to an extension to disable it.
ERR SLL Protocol -  Turn Off Extensions
  1. After disabling each extension, revisit the website showing the ERR_SSL_PROTOCOL_ERROR message. If the message vanishes, it means you should probably stay away from that extension.
  2. Faulty antivirus configurations and firewall settings can also lead to the SSL error message, so you may want to uninstall your antivirus. Don’t worry, as Windows Defender has your back if you do. Open Settings again on your PC.
  3. Click on “Apps -> Apps & Features.”
ERR SLL Protocol - Apps And Features
  1. Select your antivirus software and click on the “Uninstall” button.
ERR SLL Protocol -  Uninstall Applications

Good to know: learn how to use Vim shortcuts to navigate your web browser with ease.

4. Check the Website’s SSL Certificate

You can check the SSL Certificate using an online SSL by following the steps below:

  1. Open SSLChecker on your web browser.
  2. Enter the domain name and click “Check.”
ERR SLL Protocol -  Ssl Checker
  1. SSLChecker provides a complete report showing whether there’s anything wrong with that website’s certificate.

5. Disable the QUIC Protocol

Disabling the QUIC Protocol, which was designed to make HTTP traffic more secure, efficient, and fast, can sometimes fix ERR_SSL_PROTOCOL_ERROR. Here’s how to go about it:

  1. Open Chrome and type chrome://flags/#enable-quic in the URL bar and press Enter.
  2. Next to “Experimental QUIC Protocol,” open the drop-down menu and select “Disabled.”
ERR SLL Protocol - Disable Quic

6. Change Your Internet Security and Privacy Level

Internet Security and Privacy categorizes Web traffic and determines whether specific actions are permitted. If your Internet Security and Privacy levels are high, they may restrict access to several websites and cause an ERR_SSL_PROTOCOL_ERROR message.

  1. Click on the Start menu, type “Internet Options,” and press Enter.
  2. In the following window, navigate to the “Security” tab, use the slider to adjust the settings to “Medium,” and select “OK.”
ERR SLL Protocol - Adjust Security Level

Tip: you don’t have to stick to the default search engine when using a browser. Follow this guide to change it.

7. Check Your Firewall

A firewall may also interfere with the SSL protocols, but you can disable it to see if it fixes the issue for you by following the steps below:

  1. Click on the Start menu, type “Control Panel,” and press Enter.
  2. Go to “System and Security” and select “Windows Defender Firewall” in the following window.
ERR SLL Protocol -  Windows Firewall
  1. Press on the “Turn Windows Defender Firewall on or off” option.
ERR SLL Protocol -  Turn Windows Firewall On Or Off
  1. Finally, click “Turn off Windows Defender Firewall (not recommended)” for both private and public network settings and select “OK.”
ERR SLL Protocol -  Disable Windows Firewall

8. Enable All SSL/TLS Versions

Enabling all SSL/TLS versions allows your web browser to load websites with outdated or insecure protocols. This approach, although not recommended, could help you identify the source of the ERR_SSL_PROTOCOL_ERROR message in Windows. Use it as a last resort.

  1. Click on the Start menu, type “Internet Options,” and press Enter.
  2. Go to the “Advanced” tab, then check the boxes of all the “TLS/SSL” versions.
ERR SLL Protocol -  Enable Ssl Tls

As infuriating as ERR_SSL_PROTOCOL_ERROR in Windows can be, it’s thankfully not difficult to resolve. Although clearing your browser’s cache will usually solve the problem, you should be aware that some of the websites you are trying to visit may not be secure and are attempting to infect your computer. You should always avoid visiting suspicious websites, but sometimes accidents happen. For such cases, we have a guide that can help you determine whether a website is legitimate and safe to use. Hopefully, it can prevent you from going down the rabbit hole.

Image credit: Pexels. All screenshots by Farhad Pashaei.

Farhad Pashaei
Farhad Pashaei

As a technophile, Farhad has spent the last decade getting hands-on experience with a variety of electronic devices, including smartphones, laptops, accessories, wearables, printers, and so on. When he isn’t writing, you can bet he’s devouring information on products making their market foray, demonstrating his unquenchable thirst for technology.

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