This is a SOLR 6 issue which we can resolve in packaging (no need for SOLR 6.4)
The script shipped with SOLR does not use late binding in the function that wires up SSL
Another script fails to pass the correct details to Jetty.
See SEARCH-239 for the details.
Affects 5.2 + SOLR 6 on Windows + SSL (both sharded and unsharded)
Issue investigated and fixed locally.