buffchan: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/lib/news/bin/buffchan - from package: inn2
/usr/lib/news/bin/buffchan - from package: inn

You may install the required package with command apt-get install {package}

Error in other languages:
buffchan: bevel nie gevind nie
buffchan: comandă negăsită
buffchan: comando não encontrado
buffchan: commande introuvable
buffchan: command not found
buffchan: käsku ei ole
buffchan: không tìm thấy lệnh
buffchan: komanda nerasta
buffchan: Kommando nicht gefunden.
buffchan: kommandot finns inte
buffchan: komut yok
buffchan: nie znaleziono polecenia
buffchan: níor aimsíodh an t-ordú
buffchan: no se encontró la orden
buffchan: no s'ha trobat l'ordre
buffchan: opdracht niet gevonden
buffchan: parancs nem található
buffchan: perintah tidak ditemukan
buffchan: príkaz nenájdený
buffchan: příkaz nenalezen
buffchan: команда не найдена
buffchan: командата не е открита
buffchan: 命令找不到
buffchan: コマンドが見つかりません