I just found this:
aborrero@tools-sgebastion-06:~$ sudo systemctl status user-.slice ● user-.slice Loaded: error (Reason: Invalid argument) Drop-In: /etc/systemd/system/user-.slice.d └─puppet-override.conf Active: inactive (dead) Feb 04 11:14:26 tools-sgebastion-06 systemd[1]: [/etc/systemd/system/user-.slice.d/puppet-override.conf:11] Memory limit '0' out of range. Ignoring. Feb 04 11:14:26 tools-sgebastion-06 systemd[1]: [/etc/systemd/system/user-.slice.d/puppet-override.conf:14] Unknown lvalue 'IPAccounting' in section 'Slice' Feb 04 11:14:26 tools-sgebastion-06 systemd[1]: user-.slice: Slice name user-.slice is not valid. Refusing. aborrero@tools-sgebastion-06:~$ apt-cache policy systemd systemd: Installed: 232-25+deb9u8 Candidate: 232-25+deb9u8 Version table: 239-12~bpo9+1 100 100 http://mirrors.wikimedia.org/debian stretch-backports/main amd64 Packages *** 232-25+deb9u8 500 500 http://security.debian.org stretch/updates/main amd64 Packages 100 /var/lib/dpkg/status 232-25+deb9u6 500 500 http://deb.debian.org/debian stretch/main amd64 Packages
- We have the wrong systemd version installed
- We have some typo in the config