mkstub: 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/mkstub - from package: gnome-libs-devel

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

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