idconvert: 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/idconvert - from package: libpwiz-tools

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

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