dmassagevendor: 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/sbin/dmassagevendor - from package: arpwatch

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