acheck: 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/acheck - from package: acheck

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

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