Thank you!
For me using snapshot 2.4 this combination of the solutions above still solved the problem:
- change the false pathways in file /lib/systemd/system/openhab2.service as suggested by @m3ld0n
- remove the service file in other location as described by @Benjy on May 20th
- create directories: /usr/share/openhab2/userdata, /usr/share/openhab2/userdata/tmp, /usr/share/openhab2/userdata/etc as described by @Robin_Keith June '17
- check openhab:openhab access to folders using openhab-cli info ( as suggested here )
- run sudo openhab-cli clean-cache as I found here