Problem:
You want to setup OpenVPN on your Raspberry Pi but you see an error message like
Fri Jun 26 18:12:35 2020 ERROR: Cannot open TUN/TAP dev /dev/net/tun: No such device (errno=19) Fri Jun 26 18:12:35 2020 Exiting due to fatal error
Solution:
This error occurs if you’ve installed OpenVPN using sudo apt install -y openvpn but if you didn’t reboot after installing it. In order to fix the issue, reboot using
sudo reboot