yodlpost: 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/yodlpost - from package: yodl

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

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