Sadly I arriving to the same conclusion as you are, something is messed up on the system, missing files or bad links.
Same error after reinstalling that package:
root@e3-2186:~# apt install libip4tc0 --reinstall
Reading package lists... Done
Building dependency tree
Thanks for the assistance, can't seem to get the log for the container that won't start (for good measure, I ran it on an already started container that I can't enter into and the returned message is as expected):
root@e3-2186:~# lxc-start -n 103 -F -l DEBUG -o /tmp/lxc-103.log...
Edit: Not sure if this is the issue (I blocked this IP in iptables, but still unable to SSH in; Chinese IP with thousands of SSH login attempts)
Jul 11 18:08:21 e3-2186 sshd: PAM 5 more authentication failures; logname= uid=0 euid=0 tty=ssh ruser= rhost=22.214.171.124 user=root
Looking for some assistance: currently running 5.4-7 and am now unable to SSH into my containers. This has seemed to occur randomly- the last time I had access was a few days ago when I edited a systemd unit service/timer in one of the containers.
The error when I try to use pct...