xmlrpc_transport: 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/xmlrpc_transport - from package: xmlrpc-c-apps

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

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