string2key: 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/string2key - from package: heimdal-libs

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

On Debian possible default full paths are:

/usr/bin/string2key - from package: heimdal-clients

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

Error in other languages:
string2key: bevel nie gevind nie
string2key: comandă negăsită
string2key: comando não encontrado
string2key: commande introuvable
string2key: command not found
string2key: käsku ei ole
string2key: không tìm thấy lệnh
string2key: komanda nerasta
string2key: Kommando nicht gefunden.
string2key: kommandot finns inte
string2key: komut yok
string2key: nie znaleziono polecenia
string2key: níor aimsíodh an t-ordú
string2key: no se encontró la orden
string2key: no s'ha trobat l'ordre
string2key: opdracht niet gevonden
string2key: parancs nem található
string2key: perintah tidak ditemukan
string2key: príkaz nenájdený
string2key: příkaz nenalezen
string2key: команда не найдена
string2key: командата не е открита
string2key: 命令找不到
string2key: コマンドが見つかりません