Have set up SSL but just get "ERR_SSL_PROTOCOL_ERROR"

I did take a look before everything went down. The SSL installation on your site was all good, and while it can take a few minutes for the certificate to become active, it took way too long for your site. Most likely there was a system issue.

The current outage means that it’s hard to verify things and the people who can fix this probably have their hands full now. But I’d be happy to get this pushed up the chain when the servers are back online.