hi. I believe that this piece of doc https://doc.ez.no/display/DEVELOPER/Solr+Bundle needs a fix. In command line example section for configuring solr6 there should be
/opt/solr/bin/solr create_core -c collection1 -d /opt/solr/server/ez/template
instead of
/opt/solr/bin/solr create_core -c collection1 -d server/ez/template

when running a current version I get following error:
Specified configuration directory server/ez/template not found!