dcopref: 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/dcopref - from package: kdelibs3

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

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