Tomcat – Could not find or load main class org.apache.catalina.util.ServerInfo

I am about to install OpenEMM on Ubuntu 16.04 and have installed previously successfully on Ubuntu 14.04. Now I am facing the problem, that somehow OpenEMM can not see tomcat running. I followed the provided docu.

Upon version check I do get the following:

openemm@rex:~/bin$ ./openemm.sh version
openemm.sh: 1.0.2
Username:   openemm
Hostname:   rex
Error: Could not find or load main class org.apache.catalina.util.ServerInfo

Tomcat can be started manualy and reached via :8080. However if I start tomcat manualy, it will run as root user not as openemm user.

The startup script provides the following:

openemm@rex:~/bin$ ./openemm.sh start
Start /home/openemm/bin/scripts/bav-update.py .. done.
Start /home/openemm/bin/scripts/bav-trigger.py .. done.
Start /home/openemm/bin/scripts/bavd.py .. done.
Start /home/openemm/bin/bav -L INFO .. done.
Start python /home/openemm/bin/scripts/recovery.py .. done.
Start /home/openemm/bin/scripts/update.py account bounce .. done.
Start /home/openemm/bin/scripts/pickdist.py .. done.
Stopping obsolete sendmail processes:   -15:4634 -15:4678 -9:4634 done.
[ ok ing sendmails:   listener [....] Starting sendmail (via systemctl): sendmail.service.
 mail queues  ADMIN  QUEUE  MIDQUEUE  SLOWQUEUE  done.
Start /home/openemm/bin/scripts/slrtscn.py .. done.
Starting up Tomcat ......
Check Java installation          :OK
Check Tomcat installation        :FAILED

Tomcat lives here:

rex:~$ ll /opt/openemm/tomcat
lrwxrwxrwx 1 root root 20 Feb  7 14:18 /opt/openemm/tomcat -> apache-tomcat-8.5.11/

What might be the problem here?