Z-stick Gen 5: Serial Error: Port /dev/ttyACM0 does not exist

I’m trying to to get my Aeon Labs z-stick Gen 5 to work on my RPi 3 but I get an error message.
“Serial Error: Port /dev/ttyACM0 does not exist”

this is what my /var/log/openhab/events.log gives me:
2017-03-05 20:12:55.931 [ThingAddedEvent ] - Thing ‘zwave:serial_zstick:ad4ba952’ has been added.
2017-03-05 20:13:04.095 [hingStatusInfoChangedEvent] - ‘zwave:serial_zstick:ad4ba952’ changed from UNINITIALIZED to INITIALIZING
2017-03-05 20:13:04.105 [hingStatusInfoChangedEvent] - ‘zwave:serial_zstick:ad4ba952’ changed from INITIALIZING to OFFLINE (BRIDGE_OFFLINE): Controller is offline
2017-03-05 20:13:04.151 [hingStatusInfoChangedEvent] - ‘zwave:serial_zstick:ad4ba952’ changed from OFFLINE (BRIDGE_OFFLINE): Controller is offline to OFFLINE (COMMUNICATION_ERROR): Serial Error: Port /dev/ttyACM0 does not exist

“ls /dev/ttyAC*” gives me back:

the installation of the RPi 3 is, RASPBIAN JESSIE LITE with java version:
java -version
java version "1.8.0_121"
Java™ SE Runtime Environment (build 1.8.0_121-b13)
Java HotSpot™ Client VM (build 25.121-b13, mixed mode)

I solved it my self, found that user openhab wasn’t in the group dialout or in the group tty.
That made it work for me