tv_validate_file: 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/tv_validate_file - from package: xmltv-util

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

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