The error 'ERR_SSL_PROTOCOL_ERROR' in a web browser typically means the browser cannot establish a secure connection with the web server.
Here are some steps that can be taken to resolve this issue:
1. Check your System's Date: Make sure the system date and time are correct. If the date and time are incorrect, the SSL certificate may appear invalid and cause the error.
2. Clear Browsing Data: Clear the cache, cookies, and browsing history of the web browser. This can be done through the browser settings or preferences.
3. Clear Your SSL State: Clear the SSL state of the browser. In Google Chrome, this can be done by going to the 'Settings' menu, then 'Advanced', then 'Privacy and security', then 'Clear browsing data', and select 'Cookies and other site data' and 'Cached images and files.'
4. Verify SSL Certificate: Ensure that the SSL certificate of the website is valid and up-to-date. Check if there is a problem with the DNS settings and if the domain name has fully propagated yet.
5. Check the Website URL: Double-check the URL of the website you're trying to access. Make sure you're entering the correct URL and that it's spelled correctly. Sometimes a simple typing mistake can cause an SSL error.
6. Enable All SSL/TLS Versions: One way to fix the ERR_SSL_PROTOCOL_ERROR is to activate all SSL/TLS versions, which can allow websites with outdated or insecure protocols to load. This method is not usually recommended but can help identify the source of the error.
To activate all SSL/TLS versions, go to the Advanced Settings in Chrome and click on System. Then select Open proxy settings and go to the Advanced tab. Click on the boxes of all the TLS/SSL versions, reload your browser, and try reaccessing the website.
7. Try Using Another Browser: If the error persists, use a different browser. Some browsers have built-in SSL certificate verification, which can cause issues if the certificate is invalid. Try using a different browser to see if the error goes away.
Following the above steps, you can resolve the 'ERR_SSL_PROTOCOL_ERROR' in your web browser. If you're still experiencing the error after trying these solutions, it may be worth consulting a technical expert for additional help.