nginx error - ERR_SPDY_INADEQUATE_TRANSPORT_SECURITY

If you get the following error 

This site can’t be reached
The webpage at https://yourdomain.com/ might be temporarily down or it may have moved permanently to a new web address.
ERR_SPDY_INADEQUATE_TRANSPORT_SECURITY

Change your nginx conf as follows

server
{
    listen 443 ssl http2;
    server_name yourdomain.com;
    ...
    ssl_ciphers 'ECDHE-RSA-AES128-GCM-SHA256:AES256+EECDH:AES256+EDH';
    ...
}

Reference : CloudFlare