task_end: 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/task_end - from package: pvm-examples

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

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