You are referring to a custom mapped domain (not a .wordpress.com URL). Staff cannot issue SSL certificates for custom domains (mapped or registered at WordPress.com) at the moment.
When you're sharing links to your site, if you are sharing them with https URLs like this:
https://himmlische-antworten.net/
that will result in an error. However, provided you use an http URL like the following:
http://himmlische-antworten.net/ there should not be any problems.
