dt-danechk: 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/dt-danechk - from package: libval-bin

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

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