ive managed to proceed with the installation guide. After that was finished i added two lines at the end of /etc/default/tomcat8
a.) JAVA_OPTS=“-Djava.awt.headless=true -Xmx1024m”
b.) JAVA_OPTS=“${JAVA_OPTS} -Djava.security.egd=file:/dev/./urandom”
then i opend a browser Page and opend http://localhost:8080/xwiki
the automatic side generator startet to run. That took plenty of time and at the end it finished with an HTTP Status 500 - Internal Server Error
My installed Java Version is
And im using Debian 9 Strech (German)