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

What Causes ERR_SSL_PROTOCOL_ERROR?

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. 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:

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. 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:

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:

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. 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:

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. 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.