xml-rpc-api2cpp: 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/xml-rpc-api2cpp - from package: xmlrpc-c-apps

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

On Debian possible default full paths are:

/usr/bin/xml-rpc-api2cpp - from package: xmlrpc-api-utils

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

Error in other languages:
xml-rpc-api2cpp: bevel nie gevind nie
xml-rpc-api2cpp: comandă negăsită
xml-rpc-api2cpp: comando não encontrado
xml-rpc-api2cpp: commande introuvable
xml-rpc-api2cpp: command not found
xml-rpc-api2cpp: käsku ei ole
xml-rpc-api2cpp: không tìm thấy lệnh
xml-rpc-api2cpp: komanda nerasta
xml-rpc-api2cpp: Kommando nicht gefunden.
xml-rpc-api2cpp: kommandot finns inte
xml-rpc-api2cpp: komut yok
xml-rpc-api2cpp: nie znaleziono polecenia
xml-rpc-api2cpp: níor aimsíodh an t-ordú
xml-rpc-api2cpp: no se encontró la orden
xml-rpc-api2cpp: no s'ha trobat l'ordre
xml-rpc-api2cpp: opdracht niet gevonden
xml-rpc-api2cpp: parancs nem található
xml-rpc-api2cpp: perintah tidak ditemukan
xml-rpc-api2cpp: príkaz nenájdený
xml-rpc-api2cpp: příkaz nenalezen
xml-rpc-api2cpp: команда не найдена
xml-rpc-api2cpp: командата не е открита
xml-rpc-api2cpp: 命令找不到
xml-rpc-api2cpp: コマンドが見つかりません