Quick Summary
The "ERR_SSL_PROTOCOL_ERROR" in Chrome indicates that the browser and the website server are having trouble establishing a secure, encrypted connection using the SSL/TLS protocol. This typically means there's a mismatch in the supported protocols or encryption methods, preventing secure data exchange.
Common Causes
- Outdated Browser: An outdated version of Chrome may not support the latest SSL/TLS protocols, leading to incompatibility with websites that require newer encryption standards.
- Incorrect System Date/Time: If your computer's date and time are significantly incorrect, the SSL certificate verification process may fail because the certificate's validity period is checked against the system time.
- SSL Certificate Issues on the Website: The website's SSL certificate might be expired, invalid, or not properly configured. This prevents Chrome from verifying the identity and security of the website.
- QUIC Protocol Interference: The QUIC protocol, an experimental transport protocol, can sometimes interfere with SSL connections, leading to errors.
- Antivirus or Firewall Interference: Security software like antivirus programs or firewalls can sometimes block or interfere with SSL connections, especially if they have overly aggressive security settings or are misconfigured.
- Conflicting Chrome Extensions: Certain Chrome extensions, particularly those related to security or privacy, can sometimes conflict with SSL connections and cause errors.
- Cached SSL State: Old or corrupted SSL state can cause the browser to try to use outdated information for a secure connection.
Step-by-Step Fixes
Method 1: Update Chrome
Step 1: Click the Chrome menu (three vertical dots) in the top right corner.
Step 2: Go to Help > About Google Chrome.
Step 3: Chrome will automatically check for updates. If an update is available, download and install it, then restart Chrome.
Method 2: Check and Correct System Date/Time
Step 1: Verify that your computer's date and time are accurate.
Step 2: If the date or time is incorrect, correct it through your operating system's settings (e.g., Date & Time in Windows, System Preferences > Date & Time on macOS).
Step 3: Ensure that your time zone is also correctly set.
Method 3: Clear SSL State
Step 1: In Chrome, go to Settings > Privacy and security > Clear browsing data.
Step 2: Select the "Advanced" tab.
Step 3: Choose "All time" for the time range.
Step 4: Check the box next to "Cached images and files" and "Cookies and other site data" (or just "Cookies and other site data").
Step 5: Check the box labeled "SSL certificates" (this option might be named slightly differently depending on your Chrome version, but it relates to SSL or security certificates).
Step 6: Click "Clear data".
Step 7: Restart Chrome.
Method 4: Disable QUIC Protocol
Step 1: Type chrome://flags/#enable-quic into Chrome's address bar and press Enter.
Step 2: Find the "Experimental QUIC protocol" flag.
Step 3: Change the setting from "Default" or "Enabled" to "Disabled".
Step 4: Restart Chrome when prompted.
Method 5: Disable Antivirus/Firewall Temporarily (For Testing)
Step 1: Temporarily disable your antivirus software or firewall.
Step 2: Try accessing the website again.
Step 3: If the error is resolved, configure your antivirus/firewall to allow connections to the website or Chrome itself. Important: Re-enable your antivirus/firewall after testing.
Method 6: Disable Chrome Extensions
Step 1: Type chrome://extensions in the address bar and press Enter.
Step 2: Disable all extensions.
Step 3: Restart Chrome and check if the issue persists.
Step 4: If the error is resolved, re-enable extensions one by one to identify the problematic extension.