expect_decryptdir: 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/expect_decryptdir - from package: expect

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