tvnamer: 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/tvnamer - from package: tvnamer

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

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