I regularly SSH to my computers and servers and, on some of them, I was getting the following warning message:
'ansi+tabs': unknown terminal type.
This was just a warning and everything worked perfectly. But, still, having a warning message was not very, ahem, professional…
I have just found the cure: you need to have additional terminal definitions installed on the remote computer. On Red Hat / CentOS / Fedora, do:
dnf install ncurses-term
and on Debian, CentOS and derivatives:
apt-get install ncurses-term
and everything will be fine.