It's been a while since I saw this.

"tmux: need UTF-8 locale (LC_CTYPE) but have ANSI_X3.4-1968"

Answer: https://nu.federati.net/url/274467

(1) edit /etc/locale.gen and uncomment a line with UTF-8 in it.
(2) run locale-gen with root permissions

#tmux #utf-8 #locales #locale.gen #locale-gen #terminal