The ERR_SSL_PROTOCOL_ERROR is a common issue that many users face when trying to access a website. This error is typically related to issues with the SSL (Secure Sockets Layer) protocol or the website's certificate. Although it can be frustrating, there are several straightforward steps you can take to resolve this issue.

1. Check Date and Time Settings

Incorrect date and time settings can interfere with the SSL connection. Follow these steps to ensure that your system’s date and time are correct:

• On Windows, open the Control Panel and go to Date and Time. Make sure your time zone is correct and that the time is accurate.
• On macOS, open System Preferences, select Date & Time, and make sure the settings are accurate.

2. Clear Browser Cache and Cookies

Cached data and cookies can sometimes cause SSL errors. Here’s how to clear them:

• Google Chrome: Click on the three dots in the upper-right corner, go to Settings > Privacy and security > Clear browsing data.
• Firefox: Click on the three horizontal lines in the upper-right corner, go to Options > Privacy & Security > Clear Data.

3. Disable Browser Extensions

Sometimes, a browser extension can cause SSL errors. Try disabling all extensions and accessing the website again:

• Google Chrome: Open the three-dot menu, go to More tools > Extensions, and toggle off all extensions.
• Firefox: Open the three-line menu, go to Add-ons > Extensions, and disable all extensions.

4. Update Browser

An outdated browser might not support the latest SSL protocols and certificates. Make sure your browser is up-to-date:

• Google Chrome: Click on the three dots in the upper-right corner, go to Help > About Chrome. Chrome will check for updates and install them if available.
• Firefox: Click on the three horizontal lines in the upper-right corner, go to Help > About Firefox. Firefox will automatically check for updates.

5. Disable QUIC Protocol

The QUIC protocol may sometimes interfere with SSL. Disabling it might resolve the issue:

Google Chrome:

• Type chrome://flags/ into the address bar and press Enter.
• Scroll down or use the search bar to find Experimental QUIC Protocol.
• Set it to Disabled and restart Chrome.

6. Ensure the Website’s SSL Certificate is Valid

Check if the website's SSL certificate has expired or if it's from an untrusted issuer. You can use online tools like SSL Checker to verify the website’s certificate status.

7. Check Firewall and Antivirus Settings

Sometimes, your firewall or antivirus software can block SSL connections. Temporarily disable them to see if they are the cause of the issue:

• Access your firewall or antivirus settings, and look for options related to SSL or HTTPS scanning. Disable these features if possible and try accessing the website again.

By following these steps, you should be able to resolve the ERR_SSL_PROTOCOL_ERROR and access the website again. If the issue persists, it might be worth contacting the website administrator for further assistance.