mhf_tickle: command not found

Have You tried accessing the binary with the full path?

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/mhf_tickle - from package: pvm-examples

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