kpasswd.heimdal: 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/kpasswd.heimdal - from package: heimdal-clients

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

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