knewsd: 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/bin/knewsd - from package: knews

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

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