owserver: 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 Debian possible default full paths are:

/usr/bin/owserver - from package: owserver

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

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