kdialog: 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/kdialog - from package: kdebase

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

On Debian possible default full paths are:

/usr/bin/kdialog - from package: kde-baseapps-bin

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

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