swkon: 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
/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 Debian possible default full paths are:

/usr/bin/swkon - from package: kon2

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