kio_svn_helper: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH

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/kio_svn_helper - from package: kdesdk

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

On Debian possible default full paths are:

/usr/bin/kio_svn_helper - from package: kdesdk-kio-plugins

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