multiwatch: 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/multiwatch - from package: multiwatch

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

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