list_titles: 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 CentOS possible default full paths are:

/usr/bin/list_titles - from package: libbluray

You may install the required package with command yum install {package}

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