gkbd-indicator-plugins-capplet: 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/gkbd-indicator-plugins-capplet - from package: libgnomekbd-capplet

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

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