We are aware of the issues you are having to select your main language for the game.
While we work on a definitive solution, we have prepared 2 tutorials, 1 in English and 1 in Spanish so you can play the game in any of the 5 languages without issues.
http://steamcommunity.com/app/324090/discussions/0/412448792357719259/
http://steamcommunity.com/app/324090/discussions/0/412448792357470564/
Thanks for your understanding and sorry for the inconveniences.
@Your FCS team.