OpenVPN not working

Hello,
i just tried to setup an OpenVPN and it can’t connect to any VPN. In the logs i can read that the " TUN/TAP adapter is missing in /dev/net/tun".

Can anyone help me fix this?

Thank you very much!

Client or server?

From where to where?

Client or server?

Can you post your logs here and the command you generate the logs with?