pct-scanner-script: 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/pct-scanner-script - from package: pct-scanner-scripts

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