fix_url.pyc: command not found

Have You tried accessing the binary with the full path?

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/lib/mailman/bin/fix_url.pyc - from package: mailman

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