If you discover a bug in Fatum, you can share your experience on the Paradox Forums mod page dedicated for bug reporting. Personal for now, I'll eventually make a dedicated twitter account if the mod got some attention.
Paradox Interactive/Crusader Kings 2/mod/ Documentation
To be honest, the project hasn't chenged a lot since 2013, I'm not even sure it can still run today with the last expansions but meh, if someone wants to continue the project.
Fatum is a total conversion mod for Crusader Kings 2 starting in the 1850s to the current days showcasing the mafia and gangsters factions of New-York City.