The CATALINA_BASE cant't be read / The <CATALINA_HOME>/conf/server.xml can't be read
$ sudo chown -R USERNAME /var/lib/tomcat8
$ sudo chown -R USERNAME /usr/share/tomcat8
$ sudo chown -R USERNAME /etc/tomcat8
$ sudo chown -R USERNAME /var/log/tomcat8
http://razius.com/articles/installing-and-adding-an-external-tomcat-server-in-netbeans/