oggThumb: 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/oggThumb - from package: oggvideotools

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

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