Intermittent "site can't provide a secure connection" error



I am building an Express application with nodejs and mysql. Most of the time I can make changes, restart the server and preview the site normally. But every now and again, instead of the landing page I get the following error page:

This site can’t provide a secure connection uses an unsupported protocol.
Unsupported protocol
The client and server don’t support a common SSL protocol version or cipher suite.

I have not been able to establish why this is via Google and hoping somebody might know where I’m going wrong please?