tknewsbiff: 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 CentOS possible default full paths are:

/usr/bin/tknewsbiff - from package: expectk

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/tknewsbiff - from package: expect

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

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