I'm trying to upgrade from Solr 8.5.2 to Solr 9.1 After installing the software and starting the instance I cannot connect, receiving such messages as curl: (7) Failed connect to hostname:port; Connection refused
I cannot connect through a browser either. Attempts to connect do not show up in solr.log (but if I use zkcli.sh to implement security.json, that does show up in solr.log: note that I cannot connect when there is no security.json, so that is not the issue). Is there some under-documented security control preventing connection?
