The current pre-release of the client ("pioneer" in the version) is only compatible to itself. So you can only play with other testers. Please be aware!
@rowey said in New client installation error:
you need to host or join a game first to download all the faf related changes
A-ah!
That did it, thanks!
I believe this would be an usefull thing to mention in the FAQs (if it's already there then, sorry I must have missed it).