Check if error ERR_BAD_SSL_CLIENT_AUTH_CERT still occurs. Solution 4: Check for and Install Windows Update (If Available) An outdated Windows operating system can also cause issues on your computer.

What is Err_spdy_protocol_error? ERR_SPDY_PROTOCOL_ERROR indicates that the web page you’re trying to access is unavailable, which indicates that the browser no longer supports the SPDY protocol.

Fix common SSL Connection errors in your Chrome, Firefox, Edge, etc, browser. Some of them can be fixed at your end while others need changes on the server.

To fix this you will need to perform a series of troubleshooting steps. Mozilla Firefox is a free to download open source browser that’s available for Windows, macOS, Linux, and Android.