net::ERR_SPDY_PROTOCOL_ERROR What is SPDY SPDY, developed by Google, is a networking protocol. It ensures fast web page download. When can you encounter the spdy error? SPDY needs SSL/TLS (Secure Sockets Layer)/(Transport Layer Security) communication security to work. That’s the reason a lot of users encounter this error when visiting secure websites. Some common examples of secure websites with HTTPS pages are YouTube, Google, Gmail etc. But you can also encounter the SPDY error when visiting non-HTTPs websites. These websites use TCP (Transmission Control Protocol). SPDY also supports this protocol and throws the error when a user visits these websites. Although common in Google Chrome, you may also face this glitch in Mozilla Firefox and Internet Explorer. What causes err_spdy_protocol_error When you visit a webpage, your browser sends a request using SPDY protocol. An outdated browser will trigger an old version of SPDY. Since Google only su...