WireGuard - “RTNETLINK answers: Operation not supported”
If you are trying to establish a WireGuard connection with a wg-quick command and receive the following error..:
$ ip link add dev wg0 type wireguard RNETLINK answers: Operation not supported Unable to access interface: Protocol not supported
..most likely the wireguard kernel module is not loaded in your system. To fix this, open the terminal and run the following command:
$ sudo modprobe wireguard
In case the issue is still there, reboot your machine.
A chance exists that the Secure Boot feature is blocking the unsigned WireGuard kernel module. In this case, you might consider either disabling the Secure Boot feature or signing the WireGuard module to raise the trust level.