tsnullshaper: 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/tsnullshaper - from package: opencaster

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

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