amcryptsimple: 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 CentOS possible default full paths are:

/usr/sbin/amcryptsimple - from package: amanda-server

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/sbin/amcryptsimple - from package: amanda-common

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

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