Hi Thomas, can you please investigate further on Ondřej's suggestion (apparmor).
Please check out this for information on how to verify it: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=900398#10 Is there any chance that you are using a "non official kernel"? What is the systemd version installed on your system? $ uname -r $ dpkg -l | grep systemd Faustin
