cat /usr/lib/systemd/system/openhab2.service
[Unit]
Description=openHAB 2 - empowering the smart home
Documentation=http://docs.openhab.org
Documentation=https://community.openhab.org
Wants=network-online.target
After=network-online.target
[Service]
EnvironmentFile=/etc/default/openhab2
User=openhab
Group=openhab
WorkingDirectory=/usr/share/openhab2
#PermissionsStartOnly=true
#ExecStartPre=/usr/share/openhab/bin/setpermissions.sh
ExecStart=/usr/share/openhab2/start.sh server
ExecStop=/usr/share/openhab2/runtime/bin/stop
# Shutdown delay in seconds, before process is tried to be killed with KILL (if configured)
TimeoutStopSec=120
Restart=on-failure
[Install]
WantedBy=multi-user.target
Maybe something didn’t go well with the upgrade…
Can you try to re-install OH 2.1? (although… it still looks like you have permission problems)
Backup your /etc/openhab2/ and /var/lib/openhab2/ directories
(see here how to: http://docs.openhab.org/installation/linux.html#backup-and-restore)
then:
sudo systemctl stop openhab2
sudo apt-get remove openhab2
sudo apt-get install openhab2
sudo systemctl daemon-reload
sudo systemctl enable openhab2
sudo systemctl start openhab2
With apt-get remove, the config files will not be removed from their places (e.g. /etc/openhab2/ and /var/lib/openhab2/jsondb) so you shouldn’t need to restore them. Don’t use apt-get purge (this will remove the config dirs & files also) 
Thanks a lot.
I did it, but I get the same
Jul 12 20:29:05 CASA-GB start.sh[11150]: at org.eclipse.osgi.storage.Storage.getInfoInputStream(Storage.java:1777)
Jul 12 20:29:05 CASA-GB start.sh[11150]: at org.eclipse.osgi.storage.Storage.(Storage.java:128)
Jul 12 20:29:05 CASA-GB start.sh[11150]: at org.eclipse.osgi.storage.Storage.createStorage(Storage.java:87)
Jul 12 20:29:05 CASA-GB start.sh[11150]: at org.eclipse.osgi.internal.framework.EquinoxContainer.(EquinoxContainer.java:75)
Jul 12 20:29:05 CASA-GB start.sh[11150]: at org.eclipse.osgi.launch.Equinox.(Equinox.java:31)
Jul 12 20:29:05 CASA-GB start.sh[11150]: at org.eclipse.osgi.launch.EquinoxFactory.newFramework(EquinoxFactory.java:24)
Jul 12 20:29:05 CASA-GB start.sh[11150]: at org.apache.karaf.main.Main.launch(Main.java:253)
Jul 12 20:29:05 CASA-GB start.sh[11150]: at org.apache.karaf.main.Main.main(Main.java:177)
Jul 12 20:29:05 CASA-GB systemd[1]: openhab2.service: Main process exited, code=exited, status=255/n/a
Jul 12 20:29:05 CASA-GB stop[11336]: stop: Ignoring predefined value for KARAF_HOME
After deleting everything and installing again, its working.
Thanks for your help.