So, when I create a custom faction (using the tool in the game, otherwise I wouldn't put this in the support forum), I can use that faction in the proceeding game I create. But, if I start another game after that, the game crashes while setting up players. If I delete and recreate that faction, it works again (until the next game after that).
The Debug seems to reference a problem when creating the Tech Tree.
Is anyone else seeing this?