hash_exp: 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/hash_exp - from package: staden-io-lib-utils

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

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