connman-vpnd: 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/sbin/connman-vpnd - from package: connman-vpn

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

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