Up until recently I'd been playing with the new Retribution content as the Drath, but for whatever reason, all my Retribution content has disappeared from the game. The Retribution Factions themselves can't even be selected, they aren't even an option. My game is version 3.5 and I've tried disabling mods, validating files, checking if I've accidentally opted into a beta, reinstalling each DLC individually through Steam, and even trying for a full fresh reinstall. The game shows the Drath customization stuff in the editors, and the game files themselves show the DLC is installed, it just can't be played.
I'm at the point where I'm ready to refund it and repurchase Retribution through Steam to see if that would work, though it's pretty unlikely it will.