This is the third time I've been unable to log out; the problem:

$ cat /etc/resolv.conf # Generated by NetworkManager $

Any ideas why? (NB, this is a really complex setup consisting of an archaic item of technology termed a "network cable" and a very non-standard configuration of a "fixed IP address".)

Once is an accident. Twice is coincidence. Three times is an enemy action. $ sudo apt-get purge network-manager