acdvalid: 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/acdvalid - from package: emboss

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

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