het_import: 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/het_import - from package: csound-utils

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

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