acr-sh: 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/acr-sh - from package: acr

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