sash: 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:

/bin/sash - from package: sash

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