ontv-dbus: 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/bin/ontv-dbus - from package: ontv

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