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!
installing FAF in linux is a pain in the ass so i did not want to go down that path but i also figured out why i was getting the error.
FAF is installed on my linux drive and so is the game but For some reason if i dont have my external hdd pluged in FAF gives me error 127.