rkward: 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/rkward - from package: rkward

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

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