Got an error in my save after i spawned an immortal light fleet (doing the Originem quests for prime parts/blueprints). I spawned the fleet/accepted the quest and then immediately saved/quit the game as i had to leave and figured that was a good stopping point.
Discussing in the discord, this appears to be the error relating to the fleet:
public void advanceInCampaign(FleetMemberAPI member, float amount) {
CampaignFleetAPI fleet = member.getFleetData().getFleet();
I've attached the whole log file though. Error starts on line 442347.
[attachment deleted by admin]