paths.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/paths.pyc - from package: mailman

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