Sure, I have installed cncnet on the Linux Host as well (it's using Wine) and as I wrote, the client can indeed connect to cncnet.org, but afterwards I cannot join the game of my friend, who is running his cncnet installation on Windows (allegedly our version of something differs, I have v1.36, he has v1.38, though I have no idea what this version number refers to). That is why I decided to replicate the same installation as he has on Windows. And there I hit this wall.